Author: "Grzegorz Dudziński" - Searchworks@Jio Institute Digital Library Search Results

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27 results on '"Grzegorz Dudziński"'

1. Gaia@home: Combining Gaia catalogue with the power of volunteer computing

Author: Przemysław Bartczak, Toni Santana-Ros, Arkadiusz Hypki, Krzysztof Langner, and Grzegorz Dudziński
Abstract: The Gaia@home project is designed to give scientists another layer of freedom. The project makes possible to perform computations which demand a lot of CPU time – reducing the computational workload and opening up opportunities for heavy processing operations on volunteers computers.Gaia@home allows to create a huge number of small jobs (Gaia data + code), send them to the BOINC platform and collect the results for further analysis.Enjoy Gaia@home either if you are a scientist looking for CPU resources or a volunteer willing to contribute to citizen science. Figure 1. Gaia@home logo. Are you a scientist? Gaia@home can speed up your science! Step 1: Visit https://web.gaiaathome.eu/login and create an account Step 2: Prepare the code used for your calculations following some BOINC rules. Instructions are provided in our site. The code can compute any scientific problem which relies on the Gaia archive data, but also feel free to attach your own data. Step 3: Create a new task. Every task consists of the executable file, compiled according to BOINC guidance (step 2), auxiliary files (e.g. additional input file needed for any job) and a prescription on how to split Gaia archive into a series of parallel, independent jobs. Every BOINC job gets these files, and one portion of the data from the Gaia archive. Step 4: Your task starts running and you will be notified when a number of jobs on the BOINC platform have been completed. Step 5: You will be periodically notified by email about the status of your calculations. Finally, you will be notified when the task is completed and you are ready to download your results! Figure 2. Screenshot of Gaia@home showing the current available computation resources from volunteers. Would you like to contribute to citizen science? Volunteer your free resources! Step 1: Visit http://www.gaiaathome.eu and press on Volunteer now! Step 2: Create an account in BOINC Step 3: Install BOINC app in your device, and start contributing to science! Acknowledgements This work has received funding from European Space Agence under the polish industry incentive scheme - GAVIP-GridComputing (4000120180/17/NL/CBi). TSR acknowledges funding from the NEO-MAPP project (H2020-EU-2-1-6/870377). This work was (partially) funded by the Spanish MICIN/AEI/10.13039/ the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia ‘María de Maeztu’) through grant CEX2019-000918-M.
Published: 2022

2. Constraining the shape and density of binary asteroid (121) Hermione

Author: Marin Ferrais, Pierre Vernazza, Michaël Marsset, Laurent Jorda, Benoit Carry, Josef Hanus, Miroslav Brož, Bin Yang, Romain Fétick, Franck Marchis, Frederic Vachier, Mirel Birlan, Emmanuël Jehin, Edyta Podlewska-Gaca, Przemyslaw Bartczak, Thierry Fusco, and Grzegorz Dudziński
Abstract: Context (121) Hermione is a large binary asteroid [1] located at the outer edge of the asteroid belt in the Cybele region, where asteroids are thought to be linked to the outer Solar System. Hermione has a Ch/Cgh-type that has been linked to CM chondrites. Adaptive optics observations between 2003 and 2008 suggest a rare bilobate shape for the primary [2,3]. However, Hermione’s shape and bulk density (ranging between 1.4 and 2 g.cm-3) remain poorly constrained to this day. Aim We acquired spatially resolved images and optical lightcurves of Hermione during its close apparition of September 2021. It was the best chance in 13 years to acquire such high angular resolution images (angular diameter = 0.14”). We aimed to constrain Hermione’s 3D shape, hence its volume, and the orbit of its satellite, hence the mass of the system. Combining the volume and the mass allows to constrain the bulk density with high accuracy. Methods We obtained 8 series of 5 images with the SPHERE/ZIMPOL instrument on the Very Large Telescope (ESO Program ID 107.22UT.001; PI: P. Vernazza). These images were combined with optical lightcurves and stellar occultations by the ADAM and MPCD methods [4,5] to reconstruct the asteroid’s 3D shape. For the determination of the satellite’s orbit, we complemented the SPHERE images with a compilation of archival data from other large ground-based AO instruments (KeckII/NIRC2, ESO/VLT/NACO and Gemini-North/NIRI). Then, we used the meta-heuristic algorithm Genoid [6] to accurately determine the orbital elements. Results The determined volume and mass of Hermione yield a new higher bulk density of ~1.7 g.cm-3, more compatible with its Ch/Cgh classification. We will also present our analyse of the shape and compare it with other elongated Ch/Cgh asteroids. Bibliography [1] Merline et al. (2002), IAU Circ. 7980 [2] Marchis et al. (2005), Icarus, 178, 2, p. 450-464 [3] Descamps et al. (2009), Icarus, 203, 1, p. 88-101 [4] Viikinkoski, M., Kaasalainen, M., & Durech, J. (2015), A&A, 576, A8 [5] Capanna, C., Gesquière, G., Jorda, L., Lamy, P., & Vibert, D. (2013), The Visual Computer, 29, 825 [6] Vachier, F., Berthier, J. and Marchis, F. (2012), A&1, 543, A68
Published: 2022

3. (65) Cybele is the smallest asteroid at hydrostatic equilibrium, why?

Author: Michaël Marsset, Miroslav Brož, Julie Vermersch, Nicolas Rambaux, Marin Ferrais, Matti Viikinkoski, Josef Hanuš, Emmanuel Jehin, Edyta Podlewska-Gaca, Przemyslaw Bartczak, Grzegorz Dudziński, Benoit Carry, and Pierre Vernazza
Abstract: Context – Cybele asteroids constitute an appealing reservoir of primitive material genetically linked to the outer Solar system. The physical properties (size, shape) of the largest members can be directly measured with high-angular resolution imagers mounted on large (8-m class) telescopes. Aim – We took advantage of the bright apparition of the most iconic member of the Cybele population, (65) Cybele, in July and August 2021 to acquire high angular resolution images and optical light curves of the asteroid that were used to analyze its shape, topography and bulk properties (volume, density). Methods – Eight series of images were acquired with SPHERE+ZIMPOL on the Very Large Telescope (ESO Program ID 107.22QN.001; PI: Marsset) and combined with optical light curves to reconstruct the shape of the asteroid using the ADAM (Viikinkoski et al. 2015), MPCD (Capanna et al. 2013) and SAGE (Bartczak & Dudziński 2018) algorithms. Results – We will present Cybele’s bulk properties, including its volume-equivalent diameter and average density, in the context of other low-albedo P-type asteroids. We will show that Cybele’s shape and rotation state are entirely compatible to those of a Maclaurin equilibrium figure, opening up the possibility that D≥260 km (M≥1.4x10^19 kg) small bodies from the outer Solar System formed at equilibrium. We will further present the results of N-body simulations used to explore whether the equilibrium shape of Cybele is the result of a large resetting impact (similarly to the case of Hygiea; Vernazza et al. 2020), or if it is primordial (i.e., the result of early internal heating due to the radioactive decay of short- and long-lived radionuclides).
Published: 2022

4. VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis

Author: J. Krajewski, P. Aurard, Philippe Lamy, Vishnu Reddy, Laurent Jorda, D. Molina, Josef Hanus, Josef Ďurech, P. Michel, F. Vachier, Nicolas Rambaux, J. Oey, Grzegorz Dudziński, P. Bartczak, A. Leroy, Michael Marsset, L. Dalmon, P. Beck, H. Le Coroller, Hiroko Hamanowa, Maëlle Neveu, Christophe Dumas, Hiromi Hamanowa, A. G. Sanchez, Zouhair Benkhaldoun, N. Payre, E. Podlewska-Gaca, Fabrice Cipriani, Raoul Behrend, Paolo Tanga, Aled Jones, Julie Castillo-Rogez, Miroslav Brož, P. Antonini, Tadeusz Michalowski, F. Livet, O. Labrevoir, J. M. Bosch, Emmanuel Jehin, Arthur Vigan, S. Fauvaud, A. Chapman, Marin Ferrais, Jérôme Berthier, Alexis Drouard, Mirel Birlan, J. Grice, R. Montaigut, J. His, L. Socha, Romain Fétick, Olivier Witasse, Pierre Vernazza, Thierry Fusco, Benoit Carry, F. Marchis, Doeon Kim, Toni Santana-Ros, Mikko Kaasalainen, Matti Viikinkoski, P. Sabin, M. Audejean, A. Marciniak, Myung-Jin Kim, Bin Yang, Agnieszka Kryszczyńska, François Colas, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institute of Astronomy [Prague], Charles University [Prague] (CU), Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Tampere University of Technology [Tampere] (TUT), Search for Extraterrestrial Intelligence Institute (SETI), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Romanian Academy, Romanian Academy, Adam Mickiewicz University in Poznań (UAM), Institut de Recherche en Horticulture et Semences (IRHS), Université d'Angers (UA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Liège, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), California Institute of Technology (CALTECH), European Space Agency (ESA), TMT Observatory, The Open University [Milton Keynes] (OU), Department of Mathematics [Tampere], University of Maryland [College Park], University of Maryland System, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Hospices Civils de Lyon (HCL), Research on Healthcare Performance (RESHAPE - Inserm U1290 - UCBL1), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM), Universidad de Alicante, Universitat de Barcelona (UB), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Observatoire de Chinon, Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Observatoire de Haute-Provence (OHP), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Geneva Observatory, University of Geneva [Switzerland], Université Cadi Ayyad [Marrakech] (UCA), Héritages et Constructions dans le Texte et l'Image (HCTI), Institut Brestois des Sciences de l'Homme et de la Société (IBSHS), Université de Brest (UBO)-Université de Brest (UBO)-Université de Bretagne Sud (UBS)-Université de Brest (UBO), Observatoire du Bois de Bardon, Association T60, Observatoire Midi-Pyrénées, Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Laboratory for Space Research [Hong Kong] (LSR), The University of Hong Kong (HKU), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Korea Astronomy and Space Science Institute (KASI), Okayama University, Chungbuk National University, Laboratoire d'analyse et de recherche en économie et finance internationales (Larefi), Université de Bordeaux (UB), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Anunaki Observatory, Sanofi-Aventis R&D, SANOFI Recherche, Planetary Science Institute [Tucson] (PSI), Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Ministerio de Economía y Competitividad (España), Belgian Science Policy Office, National Science Foundation (US), Generalitat Valenciana, Université Côte d'Azur (UCA), Université d'Angers (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois des Sciences de l'Homme et de la Société (IBSHS), Université de Brest (UBO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Tampere University, and Computing Sciences
Subjects: asteroids, Rotation period, Surface (mathematics), Shell (structure), [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], general [Minor planets, asteroids], Context (language use), Astrophysics, 01 natural sciences, 03 medical and health sciences, Física Aplicada, 0103 physical sciences, 111 Mathematics, observational [Methods], 010303 astronomy & astrophysics, 030304 developmental biology, Physics, Asteroids:general, 0303 health sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Minor planets, techniques: high angular resolution, Astronomy and Astrophysics, 113 Computer and information sciences, asteroids: general, Bimodality, high angular resolution [Techniques], Density distribution, 115 Astronomy and space science, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], minor planets, methods: observational, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [Asteroids], high angular resolution, Shape analysis (digital geometry)
Abstract: Vernazza, P., et al., Until recently, the 3D shape, and therefore density (when combining the volume estimate with available mass estimates), and surface topography of the vast majority of the largest (D ≥ 100 km) main-belt asteroids have remained poorly constrained. The improved capabilities of the SPHERE/ZIMPOL instrument have opened new doors into ground-based asteroid exploration. Aims. To constrain the formation and evolution of a representative sample of large asteroids, we conducted a high-angular-resolution imaging survey of 42 large main-belt asteroids with VLT/SPHERE/ZIMPOL. Our asteroid sample comprises 39 bodies with D ≥ 100 km and in particular most D ≥ 200 km main-belt asteroids (20/23). Furthermore, it nicely reflects the compositional diversity present in the main belt as the sampled bodies belong to the following taxonomic classes: A, B, C, Ch/Cgh, E/M/X, K, P/T, S, and V. Methods. The SPHERE/ZIMPOL images were first used to reconstruct the 3D shape of all targets with both the ADAM and MPCD reconstruction methods.We subsequently performed a detailed shape analysis and constrained the density of each target using available mass estimates including our own mass estimates in the case of multiple systems. Results. The analysis of the reconstructed shapes allowed us to identify two families of objects as a function of their diameters, namely spherical and elongated bodies. A difference in rotation period appears to be the main origin of this bimodality. In addition, all but one object (216 Kleopatra) are located along the Maclaurin sequence with large volatile-rich bodies being the closest to the latter. Our results further reveal that the primaries of most multiple systems possess a rotation period of shorter than 6 h and an elongated shape (c=a ≤ 0.65). Densities in our sample range from ∼1.3 g cm-3 (87 Sylvia) to ∼4.3 g cm-3 (22 Kalliope). Furthermore, the density distribution appears to be strongly bimodal with volatile-poor (P ≥ 2.7 g cm-3) and volatile-rich (P ≤ 2.2 g cm-3) bodies. Finally, our survey along with previous observations provides evidence in support of the possibility that some C-complex bodies could be intrinsically related to IDP-like P- and D-type asteroids, representing different layers of a same body (C: core; P/D: outer shell). We therefore propose that P/ D-types and some C-types may have the same origin in the primordial trans-Neptunian disk., We warmly thank the ESO staff at Paranal and in particular Henri Boffin for providing us precious support and advice throughout the entire observing programme. P.V., A.D., M.F., L.J. and B.C. were supported by CNRS/INSU/PNP. The work of T.S-R. was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). TRAPPIST project is funded by the Belgian Fund for Scientic Research (Fond National de la Recherche Scientique, FNRS) under the grant PDR T.0120.21. E.J. is a FNRS Senior Research Associate. F.M. is supported by the National Science Foundation under Grant No. 1743015.
Published: 2021

5. An advanced multipole model for (216) Kleopatra triple system

Author: Laurent Jorda, Josef Hanus, François Colas, Alexis Drouard, J. Grice, Julie Castillo-Rogez, Patrick Michel, Philippe Lamy, Pierre Vernazza, Josef Ďurech, Miroslav Brož, Bin Yang, Matti Viikinkoski, Franck Marchis, Tadeusz Michalowski, Marin Ferrais, Fabrice Cipriani, Thierry Fusco, Nicolas Rambaux, Olivier Witasse, Przemyslaw Bartczak, Arthur Vigan, David Vokrouhlický, Emmanuel Jehin, E. Podlewska-Gaca, Toni Santana-Ros, Frédéric Vachier, M. Pajuelo, Paolo Tanga, S. Benseguane, Romain Fétick, Christophe Dumas, Grzegorz Dudziński, Mirel Birlan, Agnieszka Kryszczyńska, S. Fauvaud, Anna Marciniak, Benoit Carry, J. Berthier, Michael Marsset, Institute of Astronomy [Prague], Charles University [Prague] (CU), Search for Extraterrestrial Intelligence Institute (SETI), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Tampere University of Technology [Tampere] (TUT), Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, SETI Institute, Ondřejov Observatory of the Prague Astronomical Institute, Czech Academy of Sciences [Prague] (CAS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire du Bois de Bardon, Astronomical Institute of Romanian Academy, Romanian Academy, Thirty Meter Telescope Observatory, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Universidad de Alicante, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Czech Science Foundation, Charles University (Czech Republic), National Science Foundation (US), National Aeronautics and Space Administration (US), Generalitat Valenciana, Ministerio de Ciencia, Innovación y Universidades (España), Fédération Wallonie-Bruxelles, and Belgian Science Policy Office
Subjects: 010504 meteorology & atmospheric sciences, fundamental parameters [Planets and satellites], Library science, FOS: Physical sciences, Astrophysics, 01 natural sciences, methods: numerical, Física Aplicada, 0103 physical sciences, Celestial mechanics, planets and satellites: fundamental parameters, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], numerical [Methods], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Minor planets, Astronomy and Astrophysics, Astrometry, celestial mechanics, asteroids: individual: (216) Kleopatra, individual: (216) Kleopatra [Asteroids], Space and Planetary Science, individual: (216) Kleopatra [Minor planets, asteroids], minor planets, astrometry, TRAPPIST, Christian ministry, Earth and Planetary Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: [Aims] To interpret adaptive-optics observations of (216) Kleopatra, we need to describe an evolution of multiple moons orbiting an extremely irregular body and include their mutual interactions. Such orbits are generally non-Keplerian and orbital elements are not constants. [Methods] Consequently, we used a modified N-body integrator, which was significantly extended to include the multipole expansion of the gravitational field up to the order ℓ = 10. Its convergence was verified against the 'brute-force' algorithm. We computed the coefficients Cℓ m, Sℓ m for Kleopatra's shape, assuming a constant bulk density. For Solar System applications, it was also necessary to implement a variable distance and geometry of observations. Our χ2 metric then accounts for the absolute astrometry, the relative astrometry (second moon with respect to the first), angular velocities, and silhouettes, constraining the pole orientation. This allowed us to derive the orbital elements of Kleopatra's two moons. [Results] Using both archival astrometric data and new VLT/SPHERE observations (ESO LP 199.C-0074), we were able to identify the true periods of the moons, P1 = (1.822359 ± 0.004156) d, P2 = (2.745820 ± 0.004820) d. They orbit very close to the 3:2 mean-motion resonance, but their osculating eccentricities are too small compared to other perturbations (multipole, mutual), meaning that regular librations of the critical argument are not present. The resulting mass of Kleopatra, m1 = (1.49 ± 0.16) × 10-12 M· or 2.97 × 1018 kg, is significantly lower than previously thought. An implication explained in the accompanying paper is that (216) Kleopatra is a critically rotating body., Broz, M. et al., This work has been supported by the Czech Science Foundation through grant 21-11058S (M. Brož, D. Vokrouhlický), 20-08218S (J. Hanuš, J. Ďurech), and by the Charles University Research program No. UNCE/SCI/023. This material is partially based upon work supported by the National Science Foundation under Grant No. 1743015. P.V., A.D., M.F. and B.C. were supported by CNRS/INSU/PNP. M.M. was supported by the National Aeronautics and Space Administration under grant No. 80NSSC18K0849 issued through the Planetary Astronomy Program. The work of TSR was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F. TRAPPIST-North is a project funded by the University of Liège, and performed in collaboration with Cadi Ayyad University of Marrakesh. E. Jehin is a FNRS Senior Research Associate.
Published: 2021

6. Evidence for differentiation of the most primitive small bodies

Author: Pierre Vernazza, Tadeusz Michalowski, Bin Yang, Matti Viikinkoski, Brian Warner, Agnieszka Kryszczyńska, Alexis Drouard, Alexander Storrs, Franck Marchis, J. Grice, François Colas, Patrick Michel, Laurent Jorda, Romain Fétick, Przemyslaw Bartczak, Arthur Vigan, Josef Ďurech, Marc Neveu, Frédéric Vachier, Julie Castillo-Rogez, Emmanuel Jehin, Michael Marsset, Josef Hanus, Nicolas Rambaux, Josselin Desmars, Mikko Kaasalainen, Marin Ferrais, Jérôme Berthier, Olivier Witasse, Philippe Lamy, Zouhair Benkhaldoun, E. Podlewska-Gaca, Fabrice Cipriani, Grzegorz Dudziński, Thierry Fusco, Raoul Behrend, Christophe Dumas, Anna Marciniak, Mirel Birlan, M. Pajuelo, Paolo Tanga, Benoit Carry, T. Santana-Ros, Mark A. Wieczorek, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Maryland [College Park], University of Maryland System, NASA Goddard Space Flight Center (GSFC), Institute of Astronomy [Prague], Charles University [Prague], Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Geneva Observatory, University of Geneva [Switzerland], Oukaimeden Observatory, University of Cadi Ayyad (UCA), Astronomical Institute of Romanian Academy, Romanian Academy, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Institut Polytechnique des Sciences Avancées (IPSA), Thirty Meter Telescope Observatory, The Open University [Milton Keynes] (OU), University of Tampere [Finland], HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), SETI Institute, Pontificia Universidad Católica del Perú (PUCP), Institute of Physics [Szczecin], University of Szczecin, Universidad de Alicante, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), Towson University [Towson, MD, United States], Center for Solar System Studies (CS3), European Southern Observatory (ESO), Czech Science Foundation, Charles University (Czech Republic), Generalitat de Catalunya, Ministerio de Ciencia, Innovación y Universidades (España), National Science Foundation (US), Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Charles University [Prague] (CU), Université de Genève = University of Geneva (UNIGE), Université Cadi Ayyad [Marrakech] (UCA), Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Tampere University, and Computing Sciences
Subjects: asteroids, Solar System, 010504 meteorology & atmospheric sciences, individual: Sylvia [Asteroids], individual: Sylvia [Minor planets, asteroids], FOS: Physical sciences, general [Minor planets, asteroids], Astrophysics, 01 natural sciences, Kuiper belt, Jupiter, Interplanetary dust cloud, Neptune, Física Aplicada, 0103 physical sciences, 111 Mathematics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Nodal precession, Sylvia, Minor planets, Astronomy and Astrophysics, general [Kuiper belt], 113 Computer and information sciences, Asteroids: general, Meteorite, 115 Astronomy and space science, 13. Climate action, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], Carbonaceous chondrite, Minor plantes, Asteroids: individual: Sylvia, Kuiper belt: general, general [Asteroids], Astrophysics - Earth and Planetary Astrophysics
Abstract: Carri, B., et al., [Context] Dynamical models of Solar System evolution have suggested that the so-called P- and D-type volatile-rich asteroids formed in the outer Solar System beyond Neptune's orbit and may be genetically related to the Jupiter Trojans, comets, and small Kuiper belt objects (KBOs). Indeed, the spectral properties of P- and D-type asteroids resemble that of anhydrous cometary dust. Aims. We aim to gain insights into the above classes of bodies by characterizing the internal structure of a large P- and D-type asteroid. [Methods] We report high-angular-resolution imaging observations of the P-type asteroid (87) Sylvia with the Very Large Telescope Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument. These images were used to reconstruct the 3D shape of Sylvia. Our images together with those obtained in the past with large ground-based telescopes were used to study the dynamics of its two satellites. We also modeled Sylvia's thermal evolution. [Results] The shape of Sylvia appears flattened and elongated (a/b 1.45; a/c 1.84). We derive a volume-equivalent diameter of 271 ± 5 km and a low density of 1378 ± 45 kg m-3. The two satellites orbit Sylvia on circular, equatorial orbits. The oblateness of Sylvia should imply a detectable nodal precession which contrasts with the fully-Keplerian dynamics of its two satellites. This reveals an inhomogeneous internal structure, suggesting that Sylvia is differentiated. [Conclusions] Sylvia's low density and differentiated interior can be explained by partial melting and mass redistribution through water percolation. The outer shell should be composed of material similar to interplanetary dust particles (IDPs) and the core should be similar to aqueously altered IDPs or carbonaceous chondrite meteorites such as the Tagish Lake meteorite. Numerical simulations of the thermal evolution of Sylvia show that for a body of such a size, partial melting was unavoidable due to the decay of long-lived radionuclides. In addition, we show that bodies as small as 130-150 km in diameter should have followed a similar thermal evolution, while smaller objects, such as comets and the KBO Arrokoth, must have remained pristine, which is in agreement with in situ observations of these bodies. NASA Lucy mission target (617) Patroclus (diameter ≈140 km) may, however, be differentiated., This work has been supported by the Czech Science Foundation through grants 20-08218S (J. Hanuš, J. Ďurech) and by the Charles University Research program No. UNCE/SCI/023. The work of TSR was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). This material is partially based upon work supported by the National Science Foundation under Grant No. 1743015.
Published: 2021

7. Volume uncertainty of (7) Iris shape models from disc-resolved images

Author: Laurent Jorda, P. Michel, Miroslav Brož, Michael Marsset, P. Bartczak, H. Le Coroller, Jérôme Berthier, Matti Viikinkoski, Paolo Tanga, Marin Ferrais, Benoit Carry, Arthur Vigan, Bin Yang, Pierre Vernazza, P. L. Lamy, Christophe Dumas, Tadeusz Michalowski, Toni Santana-Ros, Alexis Drouard, Romain Fétick, Grzegorz Dudziński, Julie Castillo-Rogez, M. Birlan, F. Vachier, S. Benseguane, Thierry Fusco, Agnieszka Kryszczyńska, E. Podlewska-Gaca, Fabrice Cipriani, Olivier Witasse, F. Marchis, Josef Hanus, Nicolas Rambaux, Emmanuel Jehin, A. Marciniak, François Colas, Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Adam Mickiewicz University in Poznań (UAM), Astronomical Observatory [Poznan], Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Charles University [Prague] (CU), Institute of Astronomy [Prague], Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), SETI Institute, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), University of Tampere [Finland], Astronomical Institute of Romanian Academy, Romanian Academy, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), TMT International Observatory, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Señal [Alicante] (DFESTS), Universidad de Alicante, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), European Project: 871149,EPN2024-RI, Czech Science Foundation, European Commission, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France
Subjects: asteroids, Surface (mathematics), Solar System, 010504 meteorology & atmospheric sciences, photometric -minor planets, Instrumentation, 01 natural sciences, Física Aplicada, 0103 physical sciences, medicine, Angular resolution, individual, Iris (anatomy), Adaptive optics, 010303 astronomy & astrophysics, individual: (7) Iris [Minor planets, asteroids], 0105 earth and related environmental sciences, Remote sensing, instrumentation, Physics, numerical [Methods], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], photometric [Techniques], Astronomy and Astrophysics, adaptive optics -methods, Light curve, adaptive optics [Instrumentation], numerical -techniques, medicine.anatomical_structure, Space and Planetary Science, Asteroid, Astrophysics::Earth and Planetary Astrophysics
Abstract: High angular resolution disc-resolved images of (7) Iris collected by VLT/SPHERE instrument are allowed for the detailed shape modelling of this large asteroid revealing its surface features. If (7) Iris did not suffer any events catastrophic enough to disrupt the body (which is very likely) by studying its topography, we might get insights into the early Solar system’s collisional history. When it comes to internal structure and composition, thoroughly assessing the volume and density uncertainties is necessary. In this work, we propose a method of uncertainty calculation of asteroid shape models based on light curve and adaptive optics (AO) images. We apply this method on four models of (7) Iris produced from independent Shaping Asteroids using Genetic Evolution and All-Data Asteroid Modelling inversion techniques and multiresolution photoclinometry by deformation. Obtained diameter uncertainties stem from both the observations from which the models were scaled and the models themselves. We show that despite the availability of high-resolution AO images, the volume and density of (7) Iris have substantial error bars that were underestimated in the previous studies., This work has been supported by the Czech Science Foundation through grant 20-08218S (JH, MB) and by the Charles University Research program No. UNCE/SCI/023. This work has been partially supported by Horizon 2020 grant no. 871149 ‘EPN-2024-RI’.
Published: 2020

8. Binary asteroid (31) Euphrosyne: ice-rich and nearly spherical

Author: Emmanuel Jehin, Josef Hanus, Christophe Dumas, Franck Marchis, Frédéric Vachier, Nicolas Rambaux, Pierre Vernazza, Romain Fétick, Marin Ferrais, Zouhair Benkhaldoun, M. Pajuelo, Paolo Tanga, Bin Yang, A. Marciniak, Olivier Witasse, Matti Viikinkoski, E. Podlewska-Gaca, Fabrice Cipriani, Ondrej Chrenko, Philippe Lamy, Laurent Jorda, François Colas, J. Grice, Tadeusz Michalowski, Julie Castillo-Rogez, Josef Ďurech, Mikko Kaasalainen, Grzegorz Dudziński, Michael Marsset, Patrick Michel, Mirel Birlan, Przemyslaw Bartczak, Alexis Drouard, Toni Santana-Ros, Jérôme Berthier, Miroslav Brož, Arthur Vigan, P. Ševeček, Benoit Carry, Thierry Fusco, Agnieszka Kryszczyńska, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Institute of Astronomy [Prague], Charles University [Prague] (CU), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), University of Tampere [Finland], Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Search for Extraterrestrial Intelligence Institute (SETI), Astronomical Institute of Romanian Academy, Romanian Academy, Oukaimeden Observatory, Université Cadi Ayyad [Marrakech] (UCA), Thirty Meter Telescope Observatory, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), DOTA, ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Pontificia Universidad Católica del Perú (PUCP), Universidad de Alicante, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Czech Science Foundation, Charles University (Czech Republic), Ministry of Education, Youth and Sports (Czech Republic), Centre National de la Recherche Scientifique (France), National Aeronautics and Space Administration (US), Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Fonds de la Recherche Scientifique (Fédération Wallonie-Bruxelles), and Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal
Subjects: individual: (31) Euphrosyne / minor planets [Asteroids], 010504 meteorology & atmospheric sciences, general [Minor planets, asteroids], FOS: Physical sciences, Astrophysics, Asteroids: individual: (31) Euphrosyne / minor planets, 01 natural sciences, Sphericity, law.invention, Techniques: high angular resolution, Impact crater, law, Física Aplicada, 0103 physical sciences, observational [Methods], Circular orbit, 010303 astronomy & astrophysics, individual: (31) Euphrosyne [Minor planets, asteroids], ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, high angular resolution [Techniques], Orbit, Asteroids: general, Methods: observational / minor planets, Space and Planetary Science, Asteroid, Satellite, observational / minor planets [Methods], Hydrostatic equilibrium, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [Asteroids], Astrophysics - Earth and Planetary Astrophysics, Shape analysis (digital geometry)
Abstract: Aims. Asteroid (31) Euphrosyne is one of the biggest objects in the asteroid main belt and it is also the largest member of its namesake family. The Euphrosyne family occupies a highly inclined region in the outer main belt and contains a remarkably large number of members, which is interpreted as an outcome of a disruptive cratering event. Methods. The goals of this adaptive-optics imaging study are threefold: to characterize the shape of Euphrosyne, to constrain its density, and to search for the large craters that may be associated with the family formation event. Results. We obtained disk-resolved images of Euphrosyne using SPHERE/ZIMPOL at the ESO 8.2 m VLT as part of our large program (ID: 199.C-0074, PI: Vernazza). We reconstructed its 3D shape via the ADAM shape modeling algorithm based on the SPHERE images and the available light curves of this asteroid. We analyzed the dynamics of the satellite with the Genoid meta-heuristic algorithm. Finally, we studied the shape of Euphrosyne using hydrostatic equilibrium models. Conclusions. Our SPHERE observations show that Euphrosyne has a nearly spherical shape with the sphericity index of 0.9888 and its surface lacks large impact craters. Euphrosyne's diameter is 268 ± 6 km, making it one of the top ten largest main belt asteroids. We detected a satellite of Euphrosyne - S/2019 (31) 1 - that is about 4 km across, on a circular orbit. The mass determined from the orbit of the satellite together with the volume computed from the shape model imply a density of 1665 ± 242 kg m-3, suggesting that Euphrosyne probably contains a large fraction of water ice in its interior. We find that the spherical shape of Euphrosyne is a result of the reaccumulation process following the impact, as in the case of (10) Hygiea. However, our shape analysis reveals that, contrary to Hygiea, the axis ratios of Euphrosyne significantly differ from those suggested by fluid hydrostatic equilibrium following reaccumulation., This work has been supported by the Czech Science Foundation through grant 18-09470S (J. Hanuš, O. Chrenko, P. Ševecˇek) and by the Charles University Research program No. UNCE/SCI/023. M.B. was supported by the Czech Science Foundation grant 18-04514J. Computational resources were supplied by the Ministry of Education, Youth and Sports of the Czech Republic under the projects CESNET (LM2015042) and IT4Innovations National Supercomputing Centre (LM2015070). P. Vernazza, A. Drouard, M. Ferrais and B. Carry were supported by CNRS/INSU/PNP. M.M. was supported by the National Aeronautics and Space Administration under grant No. 80NSSC18K0849 issued through the Planetary Astronomy Program. The work of TSR was carried out through grant APOSTD/2019/046 by Generalitat Valen-ciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F. TRAPPIST-North is a project funded by the Université de Liège, and performed in collaboration with Cadi Ayyad University of Marrakesh. E. Jehin is a FNRS Senior Research Associate.
Published: 2020

9. Physical parameters of selected Gaia mass asteroids

Author: Emmanuel Jehin, Neil Parley, E. Podlewska-Gaca, Anna Marciniak, Thomas G. Müller, Josep M. Bosch, Zouhair Benkhaldoun, Lawrence A. Molnar, L. Bernasconi, K. Sobkowiak, A. Farkas, Bojan Dintinjana, Grzegorz Dudziński, Rene Duffard, M. Audejean, Raoul Behrend, A. Chapman, K. Żukowski, Aled Jones, Erika Verebélyi, R. Poncy, Victor Ali-Lagoa, V. Asenjo, Nicolás Morales, Karolina Dziadura, J. Grice, Róbert Szakáts, R. Roy, M. Butkiewicz-Bąk, S. Geier, Bálint Seli, Przemyslaw Bartczak, D. Molina, Roman Hirsh, P. Antonini, Marin Ferrais, András Pál, Toni Santana-Ros, Herve Jacquinot, Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, European Commission, National Aeronautics and Space Administration (US), Hungarian Academy of Sciences, Hungarian Scientific Research Fund, Fonds de la Recherche Scientifique (Fédération Wallonie-Bruxelles), Université de Liège, Generalitat Valenciana, and Université Cadi Ayyad
Subjects: Solar System, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, general [Minor planets, asteroids], Context (language use), Astrophysics, 7. Clean energy, 01 natural sciences, Occultation, Física Aplicada, 0103 physical sciences, Thermal, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), photometric [Techniques], Minor planets, Astronomy and Astrophysics, Radiation mechanisms: thermal, Asteroids: general, 13. Climate action, Space and Planetary Science, Asteroid, thermal [Radiation mechanisms], Physics::Space Physics, Stellar occultation, Satellite, Astrophysics::Earth and Planetary Astrophysics, Spin (aerodynamics), general [Asteroids], Techniques: photometric, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. Thanks to the Gaia mission, it will be possible to determine the masses of approximately hundreds of large main belt asteroids with very good precision. We currently have diameter estimates for all of them that can be used to compute their volume and hence their density. However, some of those diameters are still based on simple thermal models, which can occasionally lead to volume uncertainties as high as 20-30%. Aims. The aim of this paper is to determine the 3D shape models and compute the volumes for 13 main belt asteroids that were selected from those targets for which Gaia will provide the mass with an accuracy of better than 10%. Methods. We used the genetic Shaping Asteroids with Genetic Evolution (SAGE) algorithm to fit disk-integrated, dense photometric lightcurves and obtain detailed asteroid shape models. These models were scaled by fitting them to available stellar occultation and/or thermal infrared observations. Results. We determine the spin and shape models for 13 main belt asteroids using the SAGE algorithm. Occultation fitting enables us to confirm main shape features and the spin state, while thermophysical modeling leads to more precise diameters as well as estimates of thermal inertia values. Conclusions. We calculated the volume of our sample of main-belt asteroids for which the Gaia satellite will provide precise mass determinations. From our volumes, it will then be possible to more accurately compute the bulk density, which is a fundamental physical property needed to understand the formation and evolution processes of small Solar System bodies. © ESO 2020., The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement no 687378 (SBNAF). Funding for the Kepler and K2 missions is provided by the NASA Science Mission directorate. L.M. was supported by the Premium Postdoctoral Research Program of the Hungarian Academy of Sciences. The research leading to these results has received funding from the LP2012-31 and LP2018-7 Lendulet grants of the Hungarian Academy of Sciences. This project has been supported by the Lendulet grant LP2012-31 of the Hungarian Academy of Sciences and by the GINOP-2.3.2-15-2016-00003 grant of the Hungarian National Research, Development and Innovation Office (NKFIH). TRAPPIST-South is a project funded by the Belgian Fonds de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F. TRAPPIST-North is a project funded by the University of Liege, and performed in collaboration with Cadi Ayyad University of Marrakesh. E.J. is a FNRS Senior Research Associate. "The Joan Oro Telescope (TJO) of the Montsec Astronomical Observatory (OAdM) is owned by the Catalan Government and operated by the Institute for Space Studies of Catalonia (IEEC)." "This article is based on observations made with the SARA telescopes (Southeastern Association for Research in Astronomy), whose node is located at the Kitt Peak National Observatory, AZ under the auspices of the National Optical Astronomy Observatory (NOAO)." "This project uses data from the SuperWASP archive. The WASP project is currently funded and operated by Warwick University and Keele University, and was originally set up by Queen's University Belfast, the Universities of Keele, St. Andrews, and Leicester, the Open University, the Isaac Newton Group, the Instituto de Astrofisica de Canarias, the South African Astronomical Observatory, and by STFC." "This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration." The work of TSR was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain)
Published: 2020

10. The large trans-Neptunian object 2002 TC 302 from combined stellar occultation, photometry, and astrometry data

Author: G. Scarfi, T. Pribulla, J. C. Guirado, L. Buzzi, Grzegorz Dudziński, A. Farkas-Takács, L. Mazzei, E. Meza, A. Aletti, J. M. Christille, C. Perelló, L. Morrone, V. Peris, Valerio Nascimbeni, J. Lecacheux, J. M. Madiedo, Rene Duffard, F. Mancini, Bruno Sicardy, J. Alikakos, Vassilis Charmandaris, Cs. Kiss, M. Conjat, Raoul Behrend, R. Komžík, Frédéric Vachier, Martina Maestripieri, J. Skvarc, Paolo Bacci, T. G. Mueller, Domenico Nardiello, R. Iglesias-Marzoa, F. Colas, Aleksandar Cikota, András Pál, N. Paschalis, R. Szakats, A. Campo Bagatin, P. J. Gutierrez, Giacomo Succi, Pablo Santos-Sanz, A. R. Gomes-Júnior, Gábor Marton, M. Butkiewicz-Bak, E. Varga-Verebélyi, M. Masucci, Estela Fernández-Valenzuela, V. Tsamis, Victor Ali-Lagoa, Felipe Braga-Ribas, M. Alighieri, Roberto Vieira-Martins, F. Manzano, Julio Camargo, E. Dal Canto, S. Hellmich, F. Roques, A. Vecchione, A. Navarro, Stefano Mottola, A. Noschese, Albino Carbognani, F. Lavalade, Josselin Desmars, Mónica Vara-Lubiano, Nora Morales, C. Schnabel, Mauro Bachini, Kosmas Gazeas, J. M. Mari, Przemyslaw Bartczak, W. Beisker, S. Sposetti, F. Ciabattari, A. Alvarez-Candal, Stefan Cikota, J. L. Ortiz, Marcelo Assafin, A. Marciniak, G. Benedetti-Rossi, H. Mikuz, Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante. Instituto Universitario de Investigación Informática, Astronomía y Astrofísica, European Commission, Junta de Andalucía, Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Fundações de Amparo à Pesquisa (Brasil), National Research, Development and Innovation Office (Hungary), Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, IAA-CSIC, Université de Paris, Laboratório Interinstitucional de E-Astronomia - LIneA, Federal University of Technology-Paraná (UTFPR / DAFIS), Observatório Nacional/MCTIC, University of Central Florida, 'G. Galilei' Universita Degli Studi di Padova, INAF - Osservatorio Astronomico di Padova, LAM, INAF - Osservatorio di Astrofisica e Scienza Dello Spazio, Schiaparelli Astronomical Observatory, Astronomical Observatory San Marcello Pistoiese CARA Project, Crni Vrh Observatory, University of Ljubljana, Osservatorio Astronomico di Monte Agliale, 55 Impasse de la Marjolaine, Observatorio Astronomico Iota-Scorpii, 1075 Avenue Saint Philippe, Observatoire de la Côte d'Azur, Gnosca Observatory, Osservatorio Astronomico di Tavolaia, 63 Boulevard de Brandebourg, UPMC Univ Paris 06, Universidade Federal do Rio de Janeiro (UFRJ), International Occultation Timing Association - European Section (IOTA-ES), Observatoire de Geneve, Max Planck Institut für Extraterrestrische Physik (MPE), Universidade Estadual Paulista (Unesp), Institute of Planetary Research, Universidad de Alicante, Unversidad de Alicante, Faculty of Electrical Engineering and Computing, E.O. Lawrence Berkeley National Laboratory, Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA), Research Centre for Astronomy and Earth Sciences, Institute of Physics, Slovak Academy of Sciences, MTA-ELTE Exoplanet Research Group, ELTE Gothard Astrophysical Observatory, National Observatory of Athens, University of Crete, Faculty of Science, A. Mickiewicz University, Nunki Observatory, Ellinogermaniki Agogi Observatory, Universidad de Valencia, Centro de Estudios de Física Del Cosmos de Aragón, Universidad de la Laguna, Agrupació Astronómica de Sabadell, Osservatorio Salvatore di Giacomo, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Observatorio Nacional [Rio de Janeiro], Universidad Politécnica Salesiana [Quito], Observatório Nacional/MCT, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Absolute magnitude, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics, Kuiper belt objects: individual: 2002 TC302, 01 natural sciences, Occultation, law.invention, Telescope, Photometry (optics), law, Geometric albedo, Física Aplicada, 0103 physical sciences, Trans-Neptunian object, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Earth and Planetary Astrophysics (astro-ph.EP), photometric [Techniques], Astronomy and Astrophysics, general [Kuiper belt], Astrometry, individual: 2002 TC302 [Kuiper belt objects], Kuiper belt: general, Occultations, Techniques: photometric, Light curve, Space and Planetary Science, [SDU]Sciences of the Universe [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: All authors: Ortiz, J. L.; Santos-Sanz, P.; Sicardy, B.; Benedetti-Rossi, G.; Duffard, R.; Morales, N.; Braga-Ribas, F.; Fernández-Valenzuela, E.; Nascimbeni, V.; Nardiello, D.; Carbognani, A.; Buzzi, L.; Aletti, A.; Bacci, P.; Maestripieri, M.; Mazzei, L.; Mikuz, H.; Skvarc, J.; Ciabattari, F.; Lavalade, F. Scarfi, G.; Mari, J. M.; Conjat, M.; Sposetti, S.; Bachini, M.; Succi, G.; Mancini, F.; Alighieri, M.; Dal Canto, E.; Masucci, M.; Vara-Lubiano, M.; Gutiérrez, P. J.; Desmars, J.; Lecacheux, J.; Vieira-Martins, R.; Camargo, J. I. B.; Assafin, M.; Colas, F.; Beisker, W.; Behrend, R.; Mueller, T. G.; Meza, E.; Gomes-Junior, A. R.; Roques, F.; Vachier, F.; Mottola, S.; Hellmich, S.; Campo Bagatin, A.; Alvarez-Candal, A.; Cikota, S.; Cikota, A.; Christille, J. M.; Pál, A.; Kiss, C.; Pribulla, T.; Komžík, R.; Madiedo, J. M.; Charmandaris, V.; Alikakos, J.; Szakáts, R.; Farkas-Takács, A.; Varga-Verebélyi, E.; Marton, G.; Marciniak, A.; Bartczak, P.; Butkiewicz-Baķ, M.; Dudziński, G.; Alí-Lagoa, V.; Gazeas, K.; Paschalis, N.; Tsamis, V.; Guirado, J. C.; Peris, V.; Iglesias-Marzoa, R.; Schnabel, C.; Manzano, F.; Navarro, A.; Perelló, C.; Vecchione, A.; Noschese, A.; Morrone, L., Context. Deriving physical properties of trans-Neptunian objects is important for the understanding of our Solar System. This requires observational efforts and the development of techniques suitable for these studies. Aims. Our aim is to characterize the large trans-Neptunian object (TNO) 2002 TC302. Methods. Stellar occultations offer unique opportunities to determine key physical properties of TNOs. On 28 January 2018, 2002 TC302 occulted a mv ∼ 15.3 star with designation 593-005847 in the UCAC4 stellar catalog, corresponding to Gaia source 130957813463146112. Twelve positive occultation chords were obtained from Italy, France, Slovenia, and Switzerland. Also, four negative detections were obtained near the north and south limbs. This represents the best observed stellar occultation by a TNO other than Pluto in terms of the number of chords published thus far. From the 12 chords, an accurate elliptical fit to the instantaneous projection of the body can be obtained that is compatible with the near misses. Results. The resulting ellipse has major and minor axes of 543 ± 18 km and 460 ± 11 km, respectively, with a position angle of 3 ± 1 degrees for the minor axis. This information, combined with rotational light curves obtained with the 1.5 m telescope at Sierra Nevada Observatory and the 1.23 m telescope at Calar Alto observatory, allows us to derive possible three-dimensional shapes and density estimations for the body based on hydrostatic equilibrium assumptions. The effective diameter in equivalent area is around 84 km smaller than the radiometrically derived diameter using thermal data from Herschel and Spitzer Space Telescopes. This might indicate the existence of an unresolved satellite of up to ∼300 km in diameter, which is required to account for all the thermal flux, although the occultation and thermal diameters are compatible within their error bars given the considerable uncertainty of the thermal results. The existence of a potential satellite also appears to be consistent with other ground-based data presented here. From the effective occultation diameter combined with absolute magnitude measurements we derive a geometric albedo of 0.147 ± 0.005, which would be somewhat smaller if 2002 TC302 has a satellite. The best occultation light curves do not show any signs of ring features or any signatures of a global atmosphere. © ESO 2020., This research was partially based on data taken at the Sierra Nevada Observatory, which is operated by the Instituto de Astrofisica de Andalucia (CSIC). This research is also partially based on data taken at the German-Spanish Calar Alto observatory, which is jointly operated by the Max Planck Institute fur Astronomie and the Instituto de Astrofisica de Andalucia (CSIC). Part of the results were also based on observations taken at the 1.6m telescope on Pico dos Dias Observatory. This research was partially based on observations collected at the Schmidt telescope 67/92 cm (Asiago, Italy) of the INAF - Osservatorio Astronomico di Padova. Funding from Spanish projects AYA2014-56637-C2-1-P, AYA2017-89637-R, from FEDER, and Proyecto de Excelencia de la Junta de Andalucia 2012-FQM1776 is acknowledged. We would like to acknowledge financial support by the Spanish grant AYA-RTI2018-098657-JI00 "LEO-SBNAF" (MCIU/AEI/FEDER, UE) and the financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV- 2017-0709). Part of the research received funding from the European Union's Horizon 2020 Research and Innovation Programme, under grant agreement no. 687378 and from the ERC programme under Grant Agreement no. 669416 Lucky Star. The following authors acknowledge the respective CNPq grants: FB-R 309578/2017-5; RV-M 304544/2017-5, 401903/2016-8; J.I.B.C. 308150/2016-3; MA 427700/2018-3, 310683/2017-3, 473002/2013-2. This study was financed in part by the CoordenacAo de Aperfeiacoamento de Pessoal de Nivel Superior - Brasil (CAPES) - Finance Code 001 and the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant 465376/2014-2). GBR acknowledges CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016, MA FAPERJ grant E-26/111.488/2013 and ARGJr FAPESP grant 2018/11239-8. E.F.-V. acknowledges support from the 2017 Preeminent Postdoctoral Program (P3) at UCF. C.K., R.S., A.F-T., and G.M. have been supported by the K-125015 and GINOP-2.3.2-15-2016-00003 grants of the Hungarian National Research, Development and Innovation Office (NKFIH), Hungary. G.M. was also supported by the Hungarian National Research, Development and Innovation Office (NKFIH) grant PD-128 360. R.K. and T.P. were supported by the VEGA 2/0031/18 grant. We acknowledge the use of Occult software by D. Herald.
Published: 2020
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11. The violent collisional history of aqueously evolved (2) Pallas

Author: Alexis Drouard, Franck Marchis, Romain Fétick, Arthur Vigan, Miroslav Brož, Julie Castillo-Rogez, Herve Le Coroller, Christophe Dumas, Josef Hanus, Toni Santana-Ros, Paolo Tanga, Patrick Michel, Matti Viikinkoski, Mirel Birlan, E. Podlewska-Gaca, Fabrice Cipriani, Bin Yang, Nicolas Rambaux, Mikko Kaasalainen, Thierry Fusco, Grzegorz Dudziński, Tadeusz Michalowski, Benoit Carry, Agnieszka Kryszczyńska, Przemyslaw Bartczak, P. Ševeček, Jérôme Berthier, Laurent Jorda, Josef Ďurech, Michael Marsset, François Colas, Derek C. Richardson, Marin Ferrais, A. Marciniak, Frédéric Vachier, Erik Asphaug, Pierre Vernazza, Emmanuel Jehin, Olivier Witasse, Philippe Lamy, European Commission, National Aeronautics and Space Administration (US), Generalitat Valenciana, Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Astronomical Institute of Charles University, Charles University [Prague] (CU), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Search for Extraterrestrial Intelligence Institute (SETI), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Faculty of Mathematics and Physics [Praha/Prague], Université de Liège, Les Afriques dans le monde (LAM), Sciences Po Bordeaux - Institut d'études politiques de Bordeaux (IEP Bordeaux)-Institut de Recherche pour le Développement (IRD)-Institut d'Études Politiques [IEP] - Bordeaux-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Amgen (Europe) GmbH, De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie (PACEA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Sciences Po Bordeaux - Institut d'études politiques de Bordeaux (IEP Bordeaux)-Institut de Recherche pour le Développement (IRD)-Institut d'Études Politiques [IEP] - Bordeaux-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), and Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal
Subjects: Very Large Telescope, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Asteroid (2) Pallas, Violent collisional history, Astronomy and Astrophysics, Orbital eccentricity, Astrophysics, Aqueous alteration, Albedo, 01 natural sciences, Orbital inclination, Bright spot, Impact crater, 13. Climate action, Chondrite, Asteroid, Física Aplicada, 0103 physical sciences, 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: et al., Asteroid (2) Pallas is the largest main-belt object not yet visited by a spacecraft, making its surface geology largely unknown and limiting our understanding of its origin and collisional evolution. Previous ground-based observational campaigns returned different estimates of its bulk density that are inconsistent with one another, one measurement1 being compatible within error bars with the icy Ceres (2.16 ± 0.01 g cm−3)2 and the other3 compatible within error bars with the rocky Vesta (3.46 ± 0.03 g cm−3)4. Here we report high-angular-resolution observations of Pallas performed with the extreme adaptive optics-fed SPHERE imager5 on the Very Large Telescope. Pallas records a violent collisional history, with numerous craters larger than 30 km in diameter populating its surface and two large impact basins that could be related to a family-forming impact. Monte Carlo simulations of the collisional evolution of the main belt correlate this cratering record to the high average impact velocity of ~11.5 km s−1 on Pallas—compared with an average of ~5.8 km s−1 for the asteroid belt—induced by Pallas’s high orbital inclination (i = 34.8°) and orbital eccentricity (e = 0.23). Compositionally, Pallas’s derived bulk density of 2.89 ± 0.08 g cm−3 (1σ uncertainty) is fully compatible with a CM chondrite-like body, as suggested by its spectral reflectance in the 3 μm wavelength region6. A bright spot observed on its surface may indicate an enrichment in salts during an early phase of aqueous alteration, compatible with Pallas’s relatively high albedo of 12–17% (refs. 7,8), although alternative origins are conceivable., Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 199.C-0074 (principal investigator: P.V.). This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with NASA. M.M. was supported by the National Aeronautics and Space Administration under grant number 80NSSC18K0849 issued through the Planetary Astronomy Program. This work was supported by the French Direction Générale de l’Armement (DGA) and Aix-Marseille Université (AMU). P.V., A.D. and B.C. were supported by CNRS/INSU/PNP. J.H., J.D. and P.S. were supported by the grant 18-09470S of the Czech Science Foundation and by the Charles University Research Programme number UNCE/SCI/023. M.Brož was supported by the grant 18-04514J of the Czech Science Foundation. E.J. is a F.R.S.-FNRS Senior Research Associate. The work of T.S.-R. was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 730890.
Published: 2020

12. Thermal properties of large main-belt asteroids observed by Herschel PACS

Author: M. Butkiewicz-Bąk, Róbert Szakáts, Przemyslaw Bartczak, Victor Ali-Lagoa, Anna Marciniak, A. Farkas-Takács, Gábor Marton, Pablo Santos-Sanz, Grzegorz Dudziński, Rene Duffard, T. G. Müller, Cs. Kiss, E. Podlewska-Gaca, Jose Luis Ortiz, European Commission, National Research, Development and Innovation Office (Hungary), Ministerio de Ciencia, Innovación y Universidades (España), and Junta de Andalucía
Subjects: 010504 meteorology & atmospheric sciences, general [Minor planets, asteroids], FOS: Physical sciences, Astrophysics, planetary systems [Infrared], Surveys, 01 natural sciences, Infrared: planetary systems, 0103 physical sciences, Thermal, Surface roughness, 010303 astronomy & astrophysics, Scaling, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Astronomy and Astrophysics, Light curve, Regolith, Wavelength, Minor planets, asteroids: general, Space and Planetary Science, Asteroid, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Free parameter
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Open Access funding provided by Max Planck Society., Non-resolved thermal infrared observations enable studies of thermal and physical properties of asteroids via thermo-physical models provided the shape and rotational properties of the target are well determined. We used calibration-programme Herschel PACS data (70, 100, 160 μm) and state-of-the-art shape models derived from adaptive-optics observations and/or optical light curves to constrain for the first time the thermal inertia of twelve large main-belt asteroids. We also modelled previously well-characterised targets such as (1) Ceres or (4) Vesta as they constitute important benchmarks. Using the scale as a free parameter, most targets required a re-scaling ∼5% consistent with what would be expected given the absolute calibration error bars. This constitutes a good cross-validation of the scaled shape models, although some targets required larger re-scaling to reproduce the IR data. We obtained low thermal inertias typical of large main belt asteroids studied before, which continues to give support to the notion that these surfaces are covered by fine-grained insulating regolith. Although the wavelengths at which PACS observed are longwards of the emission peak for main-belt asteroids, they proved to be extremely valuable to constrain size and thermal inertia and not too sensitive to surface roughness. Finally, we also propose a graphical approach to help examine how different values of the exponent used for scaling the thermal inertia as a function of heliocentric distance (i.e. temperature) affect our interpretation of the results. © V. Alí-Lagoa et al. 2020., The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement number 687378 (SBNAF). C.K., R.S., A.F-T., and G.M. have been supported by the K-125015 and GINOP-2.3.2-15-2016-00003 grants of the National Research, Development and Innovation Office (NKFIH), Hungary. P.S-S. acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 (MCIU/AEI/FEDER, UE). R.D. and P.S-S. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofiica de Andalucia (SEV-2017-0709); they also acknowledge financial support by the Spanish grant AYA-2017-84637-R and the Proyecto de Excelencia de la Junta de Andalucia J.A. 2012-FQM1776.
Published: 2020
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13. Asteroid (16) Psyche’s primordial shape: A possible Jacobi ellipsoid

Author: P. Bartczak, A. Marciniak, E. Podlewska-Gaca, Bin Yang, Fabrice Cipriani, Miroslav Brož, Arthur Vigan, Tadeusz Michalowski, Julie Castillo-Rogez, F. Vachier, Patrick Michel, Benoit Carry, Olivier Witasse, François Colas, Pierre Vernazza, F. Marchis, Emmanuel Jehin, P. Lamy, Josef Hanus, Matti Viikinkoski, Nicolas Rambaux, Romain Fétick, Alexis Drouard, Toni Santana-Ros, H. Le Coroller, M. Birlan, Mikko Kaasalainen, Agnieszka Kryszczyńska, Laurent Jorda, Josef Ďurech, Michael Marsset, Grzegorz Dudziński, Paolo Tanga, Marin Ferrais, Thierry Fusco, Christophe Dumas, Jérôme Berthier, Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Charles University, Charles University [Prague] (CU), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Tampere University of Technology [Tampere] (TUT), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Adam Mickiewicz University in Poznań (UAM), European Southern Observatory (ESO), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Astronomical Observatory [Poznan], Laboratoire associé de Reconnaissance cellulaire et amélioration des plantes, Institut National de la Recherche Agronomique (INRA), Department of Mathematics [Tampere], Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Northeastern University [Shenyang], European Southern Observatory, Centre National de la Recherche Scientifique (France), Czech Science Foundation, Charles University (Czech Republic), Generalitat Valenciana, European Commission, Ministerio de Economía y Competitividad (España), Tampere University, Computing Sciences, Research group: Inverse Problems, European Space Agency (ESA), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Rotation period, Solar System, asteroids: individual: (16) Psyche, 010504 meteorology & atmospheric sciences, lAsteroids: individual: (16) Psyche, individual: (16) Psyche [Asteroids], Context (language use), Astrophysics, individual: (16) Psyche [lAsteroids], 01 natural sciences, law.invention, law, Física Aplicada, 0103 physical sciences, observational [Methods], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, techniques: high angular resolution, Minor planets, Astronomy and Astrophysics, Ellipsoid, asteroids: general, Psyche, high angular resolution [Techniques], 13. Climate action, Space and Planetary Science, Asteroid, 115 Astronomy and space science, minor planets, Hydrostatic equilibrium, methods: observational, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [Asteroids], Shape analysis (digital geometry)
Abstract: Context. Asteroid (16) Psyche is the largest M-type asteroid in the main belt and the target of the NASA Psyche mission. It is also the only asteroid of this size (D> 200 km) known to be metal rich. Although various hypotheses have been proposed to explain the rather unique physical properties of this asteroid, a perfect understanding of its formation and bulk composition is still missing. Aims. We aim to refine the shape and bulk density of (16) Psyche and to perform a thorough analysis of its shape to better constrain possible formation scenarios and the structure of its interior. Methods. We obtained disk-resolved VLT/SPHERE/ZIMPOL images acquired within our ESO large program (ID 199.C-0074), which complement similar data obtained in 2018. Both data sets offer a complete coverage of Psyche's surface. These images were used to reconstruct the three-dimensional (3D) shape of Psyche with two independent shape modeling algorithms (MPCD and ADAM). A shape analysis was subsequently performed, including a comparison with equilibrium figures and the identification of mass deficit regions. Results. Our 3D shape along with existing mass estimates imply a density of 4.20 ± 0.60 g cm-3, which is so far the highest for a solar system object following the four telluric planets. Furthermore, the shape of Psyche presents small deviations from an ellipsoid, that is, prominently three large depressions along its equator. The flatness and density of Psyche are compatible with a formation at hydrostatic equilibrium as a Jacobi ellipsoid with a shorter rotation period of ∼3h. Later impacts may have slowed down Psyche's rotation, which is currently ∼4.2 h, while also creating the imaged depressions. Conclusions. Our results open the possibility that Psyche acquired its primordial shape either after a giant impact while its interior was already frozen or while its interior was still molten owing to the decay of the short-lived radionuclide 26Al., Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 199.C-0074 (principal investigator: P. Vernazza). P. Vernazza, A. Drouard, M. Ferrais and B. Carry were supported by CNRS/INSU/PNP. J.H. and J.D. were supported by grant 18-09470S of the Czech Science Foundation and by the Charles University Research Programme no. UNCE/SCI/023. E.J. is F.R.S.-FNRS Senior Research Associate. The work of TSR was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE).
Published: 2020

14. The Europlanet Telescope Network: A global collaboration in support of planetary sciences

Author: François Colas, Colin Snodgrass, Agustín Sánchez-Lavega, Günter Kargl, Grazina Tautvaisiene, I. Garate-Lopez, Manuel Scherf, Ricardo Hueso, Przemyslaw Bartczak, Grzegorz Dudziński, and E. Podlewska-Gaca
Subjects: Telescope, Engineering, Planetary science, business.industry, law, Astronomy, business, law.invention
Abstract: Planetary sciences is an exciting part of astronomy, and even though space missions are nowadays providing high-quality data from remote and in-situ measurements of the planets, asteroids and comets, ground-based observations are still yielding exciting results by providing crucial data sets for a better understanding of the diverse bodies in the Solar System. The discovery of thousands of exoplanetary systems during the last few decades further enhances the need for ground-based observations, collaboration between small telescope facilities and for strengthening the contribution of amateur astronomers to planetary sciences. Access to the Europlanet Telescope Network As part of the recently launched Europlanet 2024 Research Infrastructure (EPN 2024 RI; https://bit.ly/2Z1XA8u), a new collaboration between telescopes around the world has been started for providing coordinated observations and rapid responses in support of space missions and in following-up of new events. The so-called Europlanet Telescope Network (https://bit.ly/37SCiyj) will thereby provide professional scientists and amateur astronomers with access to an initial set of 16 telescope facilities (see Fig. 1) up to 2 m in diameter. While the network plans to draw in additional facilities and to build new collaborations, particularly in regions that are currently under-represented in planetary sciences, scientists and amateurs can now apply to visit those facilities that are already participating in the network and have their expenses reimbursed for the time needed to make their observations. This also comprises the possibility of remote observations since the network includes some robotic or remotely operated facilities. The Call for Observations (see website: https://bit.ly/2Br5LDt) runs from June 2020 until the end of 2023, and is coordinated through EPN 2024 RI, which is funded by the European Commission’s Horizon 2020 program. Fig. 1: The Europlanet Telescope Network (see also Section The Telescopes). Supporting Amateur Astronomers Besides fostering collaboration and providing access to small telescope facilities, the Europlanet Telescope Network also plans to support the integration of amateur astronomers into planetary sciences, since their observations can be of crucial importance for several scientific areas. Planetary atmospheres, for instance, is a field that benefits intensively from amateur astronomers. Their regular observations at high-spatial resolution are used by researchers to perform detailed studies of the atmosphere dynamics of Jupiter and Saturn and surveys of atmospheric activity on Neptune. They also provide excellent coverage of dust storms on Mars and complementary observations of Venus to space missions that observe over different viewing geometries. The accumulated observing time provided by amateurs makes it likely that unexpected events (such as convective storms on Jupiter and Saturn; impacts on Jupiter) are discovered by amateurs faster than by orbiting spacecraft or regular ground-based observation programs. Many amateurs supply their data to public data repositories that cover multiple planets like ALPO-Japan (http://alpo-j.sakura.ne.jp) or PVOL (http://pvol2.ehu.es/pvol2) on a daily basis, resulting in extremely fast follow-ups of interesting events. Space missions like NASA’s Juno keep excellent interactions with amateur astronomers that provide a large amount of observations to the mission through a dedicated website (https://www.missionjuno.swri.edu/junocam) used by Juno’s scientists to target some of their high-resolution observations. Advanced asteroid studies by using the GaiaGOSA web service (gaiagosa.eu) is another important example on how amateur observers can help planetary scientists. The photometric observations of asteroids provided by amateurs are essential for the determination of rotation periods. Data gathered from a few oppositions allow to determine detailed physical parameters that are crucial for determining the nature of these particular objects such as spin axis orientation, shape, and size, but also for verifying our understanding of the history of the Solar System. Recently, the data gathered by amateur observers helped to determine more precise shapes and volumes of 13 asteroids (Podlewska-Gaca et al., 2020, A&A, id.A11; see also Fig. 2) and to reveal the true nature of asteroid (10) Hygiea, which turned out to be a perfect candidate for a dwarf planet rather than an asteroid (Vernazza et al., 2020, Nature Astr., 136-141). Fig. 2: The shape of (68) Leto asteroid determined with help of GaiaGOSA observers. The Telescopes (Fig. 1): Pic du Midi Observatory, France: 1.06-m telescope Moletai Astronomical Observatory, Lithuania: 1.65-m and 35/51-cm telescopes Kryoneri Observatory, Greece: 1.2-m telescope Skalnate Pleso Observatory, Slovakia: 1.3-m and 61-cm telescopes Faulkes Telescope Project: two 2-m, nine 1-m, and ten 40-cm robotic telescopes Tartu Observatory, Estonia: 1.5-m and 60-cm telescopes, and 30-cm robotic telescope Danish 1.54-m telescope at La Silla Observatory, Chile: 1.54-m telescope Beacon Observatory, UK: 42-cm telescope Observatorie del Teide, Spain: 82-cm and 45-cm telescopes Calar Alto Observatory, Spain: 1.23-m telescope Lisnyky Observation Station, Ukraine: 70-cm telescope Chuguev Observatory, Ukraine: 70-cm telescope Terskol Peak Observatory, Ukraine: 2-m and 60-cm telescopes Konkoly Observatory, Hungary: 1-m and 80-cm telescopes Ussuriysk Astrophysical Observatory, Russia: 25-cm and 50-cm telescopes Rozhen Observatory, Bulgaria: 2-m, 60-cm, and 50/70-cm telescopes Further information available at https://bit.ly/2Br5LDt. Acknowledgements: Europlanet 2024 RI has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 871149.
Published: 2020
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15. A basin-free spherical shape as an outcome of a giant impact on asteroid Hygiea

Author: J. Grice, Mikko Kaasalainen, F. Colas, A. Chapman, Tadeusz Michalowski, Arthur Vigan, Josef Hanus, Julie Castillo-Rogez, Róbert Szakáts, Marin Ferrais, Przemyslaw Bartczak, Benoit Carry, Miroslav Brož, Laurent Jorda, Nicolas Rambaux, Matti Viikinkoski, Grzegorz Dudziński, P. Michel, Agnieszka Kryszczyńska, Rene Duffard, Michaël Gillon, Michael Marsset, Jérôme Berthier, J. Durech, Bin Yang, Mirel Birlan, Christophe Dumas, R. Hirsch, Francesca E. DeMeo, F. Vachier, P. Lamy, Toni Santana-Ros, Thierry Fusco, Zouhair Benkhaldoun, E. Podlewska-Gaca, Fabrice Cipriani, P. Ševeček, H. Le Coroller, Olivier Witasse, A. Marciniak, F. Marchis, Emmanuel Jehin, J. L. Maestre, Alexis Drouard, Romain Fétick, Pierre Vernazza, Paolo Tanga, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Charles University, Charles University [Prague] (CU), Tampere University of Technology [Tampere] (TUT), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Adam Mickiewicz University in Poznań (UAM), Institut d'Astrophysique et de Géophysique [Liège], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Centre de Biochimie Structurale [Montpellier] (CBS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Astronomical Observatory [Poznan], Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), LPHEA - Departement de Physique (LPHEA), Département de physique, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Agence Spatiale Européenne = European Space Agency (ESA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (France), Czech Science Foundation, Charles University (Czech Republic), European Commission, Université Cadi Ayyad, and Fonds de la Recherche Scientifique (Fédération Wallonie-Bruxelles)
Subjects: Rotation period, Solar System, 010504 meteorology & atmospheric sciences, Dwarf planet, VLT/SPHERE instrument, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 01 natural sciences, Sphericity, Impact crater, Física Aplicada, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Asteroide, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Basin-free, Astronomy, Astronomy and Astrophysics, Radius, Asteroid family, High-angular-resolution imaging observation, Asteroids, Asteroid, [SDU]Sciences of the Universe [physics], Hygiea, Astrophysics::Earth and Planetary Astrophysics, Spherical shape, Giant impact
Abstract: (10) Hygiea is the fourth largest main belt asteroid and the only known asteroid whose surface composition appears similar to that of the dwarf planet (1) Ceres1,2, suggesting a similar origin for these two objects. Hygiea suffered a giant impact more than 2 Gyr ago3 that is at the origin of one of the largest asteroid families. However, Hygeia has never been observed with sufficiently high resolution to resolve the details of its surface or to constrain its size and shape. Here, we report high-angular-resolution imaging observations of Hygiea with the VLT/SPHERE instrument (~20 mas at 600 nm) that reveal a basin-free nearly spherical shape with a volume-equivalent radius of 217 ± 7 km, implying a density of 1,944 ± 250 kg m− 3 to 1σ. In addition, we have determined a new rotation period for Hygiea of ~13.8 h, which is half the currently accepted value. Numerical simulations of the family-forming event show that Hygiea’s spherical shape and family can be explained by a collision with a large projectile (diameter ~75–150 km). By comparing Hygiea’s sphericity with that of other Solar System objects, it appears that Hygiea is nearly as spherical as Ceres, opening up the possibility for this object to be reclassified as a dwarf planet. © 2019, The Author(s), under exclusive licence to Springer Nature Limited., P.V., A.D. and B.C. were supported by CNRS/INSU/PNP. M.Broz was supported by grant 18-04514J of the Czech Science Foundation. J.H. and J.D. were supported by grant 18-09470S of the Czech Science Foundation and by the Charles University Research Programme no. UNCE/SCI/023. This project has received funding from the European Union's Horizon 2020 research and innovation programmes under grant agreement nos 730890 and 687378. This material reflects only the authors' views, and the European Commission is not liable for any use that may be made of the information contained herein. TRAPPIST-North is a project funded by the University of Liege, in collaboration with Cadi Ayyad University of Marrakech (Morocco). TRAPPIST-South is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F. E.J. and M.G. are F.R.S.-FNRS Senior Research Associates.
Published: 2019

16. The shape of (7) Iris as evidence of an ancient large impact?

Author: Miroslav Brož, Philippe Lamy, Anna Marciniak, Josef Ďurech, J. Grice, M. Pajuelo, Paolo Tanga, Patrick Michel, Benoit Carry, Marin Ferrais, Emmanuel Jehin, Bin Yang, Alexis Drouard, Toni Santana-Ros, Frédéric Vachier, Franck Marchis, Michael Marsset, Matti Viikinkoski, Josef Hanus, Romain Fétick, Olivier Witasse, Christophe Dumas, J. Berthier, François Colas, Julie Castillo-Rogez, Agnieszka Kryszczyńska, Tadeusz Michalowski, Mikko Kaasalainen, Grzegorz Dudziński, Pierre Vernazza, Przemyslaw Bartczak, E. Podlewska-Gaca, Mirel Birlan, Thierry Fusco, H. Le Coroller, Arthur Vigan, Laurent Jorda, Fabrice Cipriani, Astronomical Institute of Charles University, Charles University [Prague] (CU), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Search for Extraterrestrial Intelligence Institute (SETI), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), West Pomeranian University of Technology in Szczecin (ZUT), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, The Open University [Milton Keynes] (OU), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), TMT International Observatory, Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Technical University of Szczecin (TUNIV), Technical university of Szczecin, European Space Agency (ESA), TMT Observatory, and Pontificia Universidad Católica del Perú (PUCP)
Subjects: Solar System, Planetesimal, 010504 meteorology & atmospheric sciences, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, methods: numerical, Impact crater, Angular diameter, 0103 physical sciences, medicine, Iris (anatomy), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Collisional family, Astronomy and Astrophysics, 15. Life on land, medicine.anatomical_structure, 13. Climate action, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], minor planets, asteroids: individual: 7 Iris, methods: observational, Astrophysics - Earth and Planetary Astrophysics
Abstract: Asteroid (7) Iris is an ideal target for disk-resolved imaging owing to its brightness (V$\sim$7-8) and large angular size of 0.33 arcsec during its apparitions. Iris is believed to belong to the category of large unfragmented asteroids that avoided internal differentiation, implying that its current shape and topography may record the first few 100 Myr of the solar system's collisional evolution. We recovered information about the shape and surface topography of Iris from disk-resolved VLT/SPHERE/ZIMPOL images acquired in the frame of our ESO large program. We used the All-Data Asteroid Modeling (ADAM) shape reconstruction algorithm to model the 3D shape of Iris, using optical disk-integrated data and disk-resolved images from SPHERE as inputs. We analyzed the SPHERE images to infer the asteroid's global shape and the morphology of its main craters. We present the volume-equivalent diameter D$_{{\rm eq}}$=214$\pm$5 km, and bulk density $\rho$=2.7$\pm$0.3 g cm$^{-3}$ of Iris. Its shape appears to be consistent with that of an oblate spheroid with a large equatorial excavation. We identified eight putative surface features 20--40 km in diameter detected at several epochs, which we interpret as impact craters. Craters on Iris have depth-to-diameter ratios that are similar to those of analogous 10 km craters on Vesta. The bulk density of Iris is consistent with that of its meteoritic analog, namely LL ordinary chondrites. Considering the absence of a collisional family related to Iris and the number of large craters on its surface, we suggest that its equatorial depression may be the remnant of an ancient (at least 3 Gyr) impact. Iris's shape further opens the possibility that large planetesimals formed as almost perfect oblate spheroids. Finally, we attribute the difference in crater morphology between Iris and Vesta to their different surface gravities., Comment: Accepted for publication in Astronomy and Astrophysics
Published: 2019

17. Closing the gap between Earth-based and interplanetary mission observations: Vesta seen by VLT/SPHERE

Author: Olivier Witasse, Tadeusz Michalowski, Anna Marciniak, J. Berthier, Benoit Carry, Benoit Neichel, Arthur Vigan, Michael Marsset, E. Podlewska-Gaca, Marin Ferrais, P. Lamy, Laurent Jorda, Pierre Vernazza, Toni Santana-Ros, Bin Yang, Josef Hanus, Matti Viikinkoski, Franck Marchis, Frédéric Vachier, Przemyslaw Bartczak, Christophe Dumas, Mirel Birlan, R. Jl. Fétick, François Colas, Julie Castillo-Rogez, Patrick Michel, Laurent M. Mugnier, Agnieszka Kryszczyńska, M. Pajuelo, Paolo Tanga, H. Le Coroller, Fabrice Cipriani, Thierry Fusco, Alexis Drouard, Mikko Kaasalainen, Grzegorz Dudziński, Emmanuel Jehin, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Fundació Privada Observatori Esteve Duran, Charles University [Prague], Tampere University of Technology [Tampere] (TUT), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Adam Mickiewicz University in Poznań (UAM), Laboratoire d'Electronique et des Technologies de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Université de Liège, Institut d'Astrophysique et de Géophysique [Liège], Department of Mathematics [Tampere], Astronomical Observatory [Poznan], Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Amgen (Europe) GmbH, Galaxies, Etoiles, Physique, Instrumentation (GEPI), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú (PUCP), Universisty of Szczecin (Szczecin) (Institute of Physics), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Tampere University, Computing Sciences, DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Charles University [Prague] (CU), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), University of Szczecin, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), European Space Astronomy Centre (ESAC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Nanophysique Magnétisme et Optoélectronique (LNMO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Point spread function, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Context (language use), techniques: image processing, Astrophysics, 01 natural sciences, Interplanetary mission, Observatory, 0103 physical sciences, 111 Mathematics, 010303 astronomy & astrophysics, Image resolution, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Earth and Planetary Astrophysics (astro-ph.EP), techniques: high angular resolution, Astronomy and Astrophysics, asteroids: individual: Vesta, Albedo, 13. Climate action, Space and Planetary Science, Asteroid, minor planets, methods: observational, Interplanetary spaceflight, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: International audience; Context. Over the past decades, several interplanetary missions have studied small bodies in situ, leading to major advances in our understanding of their geological and geophysical properties. These missions, however, have had a limited number of targets. Among them, the NASA Dawn mission has characterised in detail the topography and albedo variegation across the surface of asteroid (4) Vesta down to a spatial resolution of 20 m pixel-1 scale. Aims: Here our aim was to determine how much topographic and albedo information can be retrieved from the ground with VLT/SPHERE in the case of Vesta, having a former space mission (Dawn) providing us with the ground truth that can be used as a benchmark. Methods: We observed Vesta with VLT/SPHERE/ZIMPOL as part of our ESO large programme (ID 199.C-0074) at six different epochs, and deconvolved the collected images with a parametric point spread function (PSF). We then compared our images with synthetic views of Vesta generated from the 3D shape model of the Dawn mission, on which we projected Vesta's albedo information. Results: We show that the deconvolution of the VLT/SPHERE images with a parametric PSF allows the retrieval of the main topographic and albedo features present across the surface of Vesta down to a spatial resolution of 20-30 km. Contour extraction shows an accuracy of 1 pixel (3.6 mas). The present study provides the very first quantitative estimate of the accuracy of ground-based adaptive-optics imaging observations of asteroid surfaces. Conclusions: In the case of Vesta, the upcoming generation of 30-40 m telescopes (ELT, TMT, GMT) should in principle be able to resolve all of the main features present across its surface, including the troughs and the north-south crater dichotomy, provided that they operate at the diffraction limit. Reduced images of Table A.1 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A6Based on observations made with ESO Telescopes at the Paranal Observatory under programme ID 199.C-0074 (PI: P. Vernazza).
Published: 2019

18. Optical observations of NEA 3200 Phaethon (1983 TB) during the 2017 apparition

Author: Hee-Jae Lee, Shuhrat A. Ehgamberdiev, Masateru Ishiguro, Y. Turayev, Grzegorz Dudziński, Dong-Heun Kim, Przemyslaw Bartczak, Zhong-Yi Lin, Tomoko Arai, Eun-Jung Choi, I. Reva, Joh-Na Yoon, Seitaro Urakawa, Young-Jun Choi, O. A. Burkhonov, Fumi Yoshida, Jintae Park, Alexander Serebryanskiy, Jin Choi, H. S. Yim, M. Krugov, Takashi Ito, Katsuhito Ohtsuka, Sang-Min Lee, K. E. Ergashev, Hong Kyu Moon, and Myung-Jin Kim
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Synodic day, Ecliptic, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Latitude, Space and Planetary Science, Asteroid, Sidereal time, Orientation (geometry), 0103 physical sciences, Longitude, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: The near-Earth asteroid 3200 Phaethon (1983 TB) is an attractive object not only from a scientific viewpoint but also because of JAXA's DESTINY+ target. The rotational lightcurve and spin properties were investigated based on the data obtained in the ground-based observation campaign of Phaethon. We aim to refine the lightcurves and shape model of Phaethon using all available lightcurve datasets obtained via optical observation, as well as our time-series observation data from the 2017 apparition. Using eight 1-2-m telescopes and an optical imager, we acquired the optical lightcurves and derived the spin parameters of Phaethon. We applied the lightcurve inversion method and SAGE algorithm to deduce the convex and non-convex shape model and pole orientations. We analysed the optical lightcurve of Phaethon and derived a synodic and a sidereal rotational period of 3.6039 h, with an axis ratio of a/b = 1.07. The ecliptic longitude (lambda) and latitude (beta) of the pole orientation were determined as (308, -52) and (322, -40) via two independent methods. A non-convex model from the SAGE method, which exhibits a concavity feature, is also presented., 14 pages, 4 figures, 1 figure in Appendix A. Accepted for publication in Astronomy & Astrophysics (A&A)
Published: 2018

19. The impact crater at the origin of the Julia family detected with VLT/SPHERE?

Author: Matti Viikinkoski, Toni Santana-Ros, M. Pajuelo, Paolo Tanga, Miroslav Brož, Emmanuel Jehin, Josef Hanus, Zouhair Benkhaldoun, F. Vachier, E. Podlewska-Gaca, Fabrice Cipriani, Bin Yang, Erik Asphaug, Laurent Jorda, Mikko Kaasalainen, Pierre Vernazza, Julie Castillo-Rogez, P. Lamy, Alexis Drouard, Grzegorz Dudziński, Josef Ďurech, P. Michel, Olivier Witasse, Michael Marsset, P. Ševeček, Michaël Gillon, Arthur Vigan, Agnieszka Kryszczyńska, F. Marchis, Jérôme Berthier, P. Bartczak, Thierry Fusco, Benoit Carry, H. Le Coroller, Mirel Birlan, A. Marciniak, Christophe Dumas, Romain Fétick, Tadeusz Michalowski, Derek C. Richardson, Brian D. Warner, F. Colas, Marin Ferrais, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Charles University, Charles University [Prague] (CU), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Search for Extraterrestrial Intelligence Institute (SETI), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), University of Szczecin, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), TMT Observatory, Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú (PUCP), Center for Solar System Studies (CS3), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), ASU School of Earth and Space Exploration (SESE), Arizona State University [Tempe] (ASU), University of Maryland [College Park], University of Maryland System, Université Cadi Ayyad [Marrakech] (UCA), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), TMT International Observatory, Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Tampere University, and Mathematics
Subjects: Physics, 010504 meteorology & atmospheric sciences, Collisional family, techniques: high angular resolution, asteroids: individual: (89) Julia, Astronomy and Astrophysics, Context (language use), Astrophysics, Asteroid family, 01 natural sciences, Parent body, methods: numerical, Impact crater, Space and Planetary Science, Asteroid, Observatory, 0103 physical sciences, 111 Mathematics, minor planets, methods: observational, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Interplanetary spaceflight, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Context.The vast majority of the geophysical and geological constraints (e.g., internal structure, cratering history) for main-belt asteroids have so far been obtained via dedicated interplanetary missions (e.g., ESA Rosetta, NASA Dawn). The high angular resolution of SPHERE/ZIMPOL, the new-generation visible adaptive-optics camera at ESO VLT, implies that these science objectives can now be investigated from the ground for a large fraction ofD≥ 100 km main-belt asteroids. The sharp images acquired by this instrument can be used to accurately constrain the shape and thus volume of these bodies (hence density when combined with mass estimates) and to characterize the distribution and topography ofD≥ 30 km craters across their surfaces.Aims.Here, via several complementary approaches, we evaluated the recently proposed hypothesis that the S-type asteroid (89) Julia is the parent body of a small compact asteroid family that formed via a cratering collisional event.Methods.We observed (89) Julia with VLT/SPHERE/ZIMPOL throughout its rotation, derived its 3D shape, and performed a reconnaissance and characterization of the largest craters. We also performed numerical simulations to first confirm the existence of the Julia family and to determine its age and the size of the impact crater at its origin. Finally, we utilized the images/3D shape in an attempt to identify the origin location of the small collisional family.Results.On the one hand, our VLT/SPHERE observations reveal the presence of a large crater (D~ 75 km) in Julia’s southern hemisphere. On the other hand, our numerical simulations suggest that (89) Julia was impacted 30–120 Myrs ago by aD~ 8 km asteroid, thereby creating aD≥ 60 km impact crater at the surface of Julia. Given the small size of the impactor, the obliquity of Julia and the particular orientation of the family in the (a,i) space, the imaged impact crater is likely to be the origin of the family.Conclusions.New doors into ground-based asteroid exploration, namely, geophysics and geology, are being opened thanks to the unique capabilities of VLT/SPHERE. Also, the present work may represent the beginning of a new era of asteroid-family studies. In the fields of geophysics, geology, and asteroid family studies, the future will only get brighter with the forthcoming arrival of 30–40 m class telescopes like ELT, TMT, and GMT.
Published: 2018
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20. Shape models and physical properties of asteroids

Author: Przemyslaw Bartczak, Toni Santana-Ros, and Grzegorz Dudziński
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astronomy, Inversion (meteorology), 01 natural sciences, Data type, Photometry (optics), 13. Climate action, Asteroid, Data quality, Radar imaging, 0103 physical sciences, Stellar occultation, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: Despite the large amount of high quality data generated in recent space encounters with asteroids, the majority of our knowledge about these objects comes from ground based observations. Asteroids travelling in orbits that are potentially hazardous for the Earth form an especially interesting group to be studied. In order to predict their orbital evolution, it is necessary to investigate their physical properties. This paper briefly describes the data requirements and different techniques used to solve the lightcurve inversion problem. Although photometry is the most abundant type of observational data, models of asteroids can be obtained using various data types and techniques. We describe the potential of radar imaging and stellar occultation timings to be combined with disk-integrated photometry in order to reveal information about physical properties of asteroids., From Assessment and Mitigation of Asteroid Impact Hazards book
Published: 2017

21. The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation

Author: Valerio Nascimbeni, J. Lecacheux, Toni Santana-Ros, Agustín Sánchez-Lavega, Pablo Santos-Sanz, L. Nerli, D. T. Koseoglu, Frédéric Vachier, V. Peris, Przemyslaw Bartczak, R. Komžík, Eda Sonbas, Cs. Kiss, Gábor Marton, C. Ries, Yavuz Güney, Marcelo Assafin, Martina Maestripieri, Josselin Desmars, T. G. Mueller, Osman Demircan, O. Erece, V. Granata, A. R. Gomes-Júnior, Francesco Marzari, Ulrich Hopp, Cahit Yeşilyaprak, N. Paschalis, A. Campo Bagatin, B. Gaehrken, Paolo Bacci, V. Tsamis, O. Satir, F. Martinelli, F. L. Rommel, Santiago Pérez-Hoyos, F. Ciabattari, R. Iglesias-Marzoa, Stefano Mottola, Ricardo Hueso, Julio Camargo, Herman Mikuz, Françoise Roques, Mohammad Shameoni Niaei, Mauro Bachini, Vassilis Charmandaris, Jose Luis Ortiz, A. Takácsné Farkas, András Pál, A. Carbognani, L. Tzouganatos, Giuseppe Leto, Aleksandar Cikota, G. Benedetti-Rossi, Roberto Vieira-Martins, Nicolás Morales, José M. Madiedo, Bruno Sicardy, Róbert Szakáts, B. E. Morgado, Theodor Pribulla, Estela Fernández-Valenzuela, M. Butkiewicz-Bąk, Afşar Kabaş, Alvaro Alvarez-Candal, Giacomo Succi, Jérôme Berthier, J. Alikakos, Ç. Püsküllü, Kamil Hornoch, W. Beisker, E. Meza, Stefan Cikota, T. Ozisik, E. Varga-Verebélyi, J. M. Christille, J. C. Guirado, Grzegorz Dudziński, L. Mazzei, J. M. Ohlert, Rene Duffard, Raoul Behrend, S. Kalkan, A. Marciniak, N. Karaman, S. Hellmich, Kosmas Gazeas, Victor Ali-Lagoa, Ozan Ünsalan, Felipe Braga-Ribas, François Colas, Petr Pravec, Diane Berard, Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Astronomía y Astrofísica, ITA, USA, GBR, FRA, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Observatorio Nacional [Rio de Janeiro], Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Observatório Nacional/MCT, Ludwig-Maximilians-Universität München (LMU), Dipartimento di Fisica, Università degli Studi di Padova = University of Padua (Unipd), Ondřejov Observatory of the Prague Astronomical Institute, Czech Academy of Sciences [Prague] (CAS), Centro Astronomico di Libbiano, Associazione Astrofili Alta Valdera, Istituto di Informatica e Telematica (IIT-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), DLR Institute of Planetary Research, German Aerospace Center (DLR), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Physik-Institut, Universität Zürich [Zürich] = University of Zurich (UZH), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Observatório do Valongo/UFRJ [Rio de Janeiro], Universidade Federal do Rio de Janeiro (UFRJ), Geneva Observatory, Université de Genève = University of Geneva (UNIGE), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), International Occultation Timing Association European Section (IOTA ES), International Occultation Timing Association European Section, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), IESL, Osserv Astrofis Catania, Ist Nazl Astrofis, TKK Helsinki University of Technology (TKK), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Department of Astrophysics, Astronomy and Mechanics Panepistimiopolis (DAAMP), National and Kapodistrian University of Athens (NKUA), Astronomical Union of Sparta [Sparta], University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), Departamento de Fı'sica Aplicada I, Escuela Tecnica Superior de Ingenieria Bilbao, Observatorio Astronomico de Valencia, Universitat de València (UV), Ondokuz Mayıs Üniversitesi, European Commission, European Research Council, Hungarian Academy of Sciences, Generalitat Valenciana, Junta de Andalucía, Ministerio de Economía, Industria y Competitividad (España), Universita degli Studi di Padova, Consiglio Nazionale delle Ricerche [Roma] (CNR), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), L2EP - Équipe Réseaux, Laboratoire d’Électrotechnique et d’Électronique de Puissance - ULR 2697 (L2EP), Centrale Lille-Haute Etude d'Ingénieurs-Université de Lille-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Centrale Lille-Haute Etude d'Ingénieurs-Université de Lille-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), University of Geneva [Switzerland], University of the Basque Country [Bizkaia] (UPV/EHU), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Czech Academy of Sciences [Prague] (ASCR), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Universität Zürich [Zürich] (UZH), PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Universidade Federal do Rio de Janeiro [Rio de Janeiro] (UFRJ), Laboratoire d’Électrotechnique et d’Électronique de Puissance - EA 2697 (L2EP), Ecole Centrale de Lille-École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Haute Etude d'Ingénieurs-Université de Lille-Ecole Centrale de Lille-École Nationale Supérieure d'Arts et Métiers (ENSAM), HESAM Université (HESAM)-HESAM Université (HESAM)-Haute Etude d'Ingénieurs-Université de Lille, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Athens [Greece] (UOA), and Universitat de València (UV)-Observatorio Astronomico de Valencia
Subjects: 010504 meteorology & atmospheric sciences, European community, Trans Neptunian Object, Dwarf planet, Haumea, FOS: Physical sciences, Library science, shape, 01 natural sciences, size, dwarf planet, Neptune, Física Aplicada, 0103 physical sciences, media_common.cataloged_instance, European union, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, media_common, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS]Physics [physics], density, 2003 EL61, Kuiper-belt, photometric-observations, collisional family, object, bodies, albedo, satellites, Uranus, Dwarf planets, Multidisciplinary, European research, Asteroid, Trans-Neptunian, Astronomy, Stellar occultation, Moons of Haumea, stellar occultation, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ring, Astrophysics - Earth and Planetary Astrophysics
Abstract: Ortiz, José Luis et. al., Haumea-one of the four known trans-Neptunian dwarf planets- is a very elongated and rapidly rotating body1-3. In contrast to other dwarf planets4-6, its size, shape, albedo and density are not well constrained. The Centaur Chariklo was the first body other than a giant planet known to have a ring system7, and the Centaur Chiron was later found to possess something similar to Chariklo's rings8,9. Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multichord stellar occultation). Secondary events observed around the main body of Haumea are consistent with the presence of a ring with an opacity of 0.5, width of 70 kilometres and radius of about 2,287 kilometres. The ring is coplanar with both Haumea's equator and the orbit of its satellite Hi'iaka. The radius of the ring places it close to the 3:1 mean-motion resonance with Haumea's spin period-that is, Haumea rotates three times on its axis in the time that a ring particle completes one revolution. The occultation by the main body provides an instantaneous elliptical projected shape with axes of about 1,704 kilometres and 1,138 kilometres. Combined with rotational light curves, the occultation constrains the three-dimensional orientation of Haumea and its triaxial shape, which is inconsistent with a homogeneous body in hydrostatic equilibrium. Haumea's largest axis is at least 2,322 kilometres, larger than previously thought, implying an upper limit for its density of 1,885 kilograms per cubic metre and a geometric albedo of 0.51, both smaller than previous estimates1,10,11. In addition, this estimate of the density of Haumea is closer to that of Pluto than are previous estimates, in line with expectations. No global nitrogen- or methane-dominated atmosphere was detected.© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved., J.L.O. acknowledges funding from Spanish and Andalusian grants MINECO AYA-2014-56637-C2-1-P and J. A. 2012-FQM1776 as well as FEDER funds. Part of the research leading to these results received funding from the European Union's Horizon 2020 Research and Innovation Programme, under grant agreement no. 687378. B.S. acknowledges support from the French grants 'Beyond Neptune' ANR-08-BLAN-0177 and 'Beyond Neptune II' ANR-11-1S56-0002. Part of the research leading to these results has received funding from the European Research Council under the European Community's H2020 (2014-2020/ERG grant agreement no. 669416 'Lucky Star'). A.P. and R.S. have been supported by the grant LP2012-31 of the Hungarian Academy of Sciences. All of the Hungarian contributors acknowledge the partial support from K-125015 grant of the National Research, Development and Innovation Office (NKFIH). G.B.-R., F.B.-R., F.L.R., R.V.-M., J.I.B.C., M.A., A.R.G.-J. and B.E.M. acknowledge support from CAPES, CNPq and FAPERJ. J.C.G. acknowledges funding from AYA2015-63939-C2-2-P and from the Generalitat Valenciana PROMETEOII/2014/057. K.H. and P.P. were supported by the project RVO:67985815. The Astronomical Observatory of the Autonomous Region of the Aosta Valley acknowledges a Shoemaker NEO Grant 2013 from The Planetary Society. We acknowledge funds from a 2016 'Research and Education' grant from Fondazione CRT. We also acknowledge the Slovakian project ITMS no. 26220120029.
Published: 2017

22. Shaping asteroid models using genetic evolution (SAGE)

Author: Grzegorz Dudziński and Przemyslaw Bartczak
Subjects: Physics, Ground truth, 010504 meteorology & atmospheric sciences, Inversion methods, Astronomy, Astronomy and Astrophysics, 01 natural sciences, Space and Planetary Science, Asteroid, Genetic Evolution, 0103 physical sciences, Stellar occultation, Astrophysics::Earth and Planetary Astrophysics, Adaptive optics, 010303 astronomy & astrophysics, Rotation (mathematics), 0105 earth and related environmental sciences
Abstract: In this work we present SAGE (Shaping Asteroid models using Genetic Evolution) asteroid modelling algorithm based solely on photometric lightcurve data. It produces non-convex shapes, rotation axes orientati and rotational periods of asteroids. The main concept behind a genetic evolution algorithm is to produce random populations of shapes and spin orientations by mutating a seed shape and iterating the process until it converges to a stable global minimum. To test SAGE we have performed tes on five artificial shapes. We have also modelled (433) Eros and (9) Meti asteroids, as ground truth observations for them exist, allowing us to validate the models. We have compared derived Eros shape with NEAR Shoem model and Metis shape with adaptive optics and stellar occultation observations as with other available Metis models from various inversion methods.
Published: 2017
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23. Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids

Author: Toni Santana-Ros, Przemyslaw Bartczak, F. Manzini, Th. Müller, I. Konstanciak, Paweł Kankiewicz, J. J. Sanabria, R. Stoss, Krzysztof Kamiński, Waldemar Ogloza, Grzegorz Dudziński, Nicolás Morales, K. Sobkowiak, Rene Duffard, L. Jerosimic, K. Żukowski, Frederick Pilcher, M. Butkiewicz-Bąk, Raoul Behrend, R. Poncy, V. Kudak, E. Kosturkiewicz, L. Bernasconi, R. Hirsch, S. Fauvaud, Tom Polakis, Aleksandar Cikota, Michal Siwak, Brian A. Skiff, R. Crippa, S. Geier, J. Horbowicz, Victor Ali-Lagoa, Karolina Dziadura, Michał Żejmo, M. Hren, P. Korlevic, P. Antonini, Dagmara Oszkiewicz, Małgorzata Bronikowska, R. Ditteon, M. Murawiecka, A. Marciniak, National Science Centre (Poland), European Commission, and Slovak Research and Development Agency
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, photometric [Techniques], Inverse transform sampling, general [Minor planets, asteroids], FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Scale (descriptive set theory), Astrophysics, Albedo, Rotation, 01 natural sciences, Amplitude, Space and Planetary Science, Asteroid, Minor planets, asteroids: general, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Scaling, Techniques: photometric, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: Marciniak, A. et. al..-- 33 p., The available set of spin and shape modelled asteroids is strongly biased against slowly rotating targets and those with low lightcurve amplitudes. This is due to the observing selection effects. As a consequence, the current picture of asteroid spin axis distribution, rotation rates, radiometric properties, or aspects related to the object's internal structure might be affected too. Aims. To counteract these selection effects, we are running a photometric campaign of a large sample of main belt asteroids omitted in most previous studies. Using least chi-squared fitting we determined synodic rotation periods and verified previous determinations. When a dataset for a given target was sufficiently large and varied, we performed spin and shape modelling with two different methods to compare their performance. Methods. We used the convex inversion method and the non-convex SAGE algorithm, applied on the same datasets of dense lightcurves. Both methods search for the lowest deviations between observed and modelled lightcurves, though using different approaches. Unlike convex inversion, the SAGE method allows for the existence of valleys and indentations on the shapes based only on lightcurves. Results. We obtain detailed spin and shape models for the first five targets of our sample: (159) Aemilia, (227) Philosophia, (329) Svea, (478) Tergeste, and (487) Venetia. When compared to stellar occultation chords, our models obtained an absolute size scale and major topographic features of the shape models were also confirmed. When applied to thermophysical modelling (TPM), they provided a very good fit to the infrared data and allowed their size, albedo, and thermal inertia to be determined. Conclusions. Convex and non-convex shape models provide comparable fits to lightcurves. However, some non-convex models fit notably better to stellar occultation chords and to infrared data in sophisticated thermophysical modelling (TPM). In some cases TPM showed strong preference for one of the spin and shape solutions. Also, we confirmed that slowly rotating asteroids tend to have higher-than-average values of thermal inertia, which might be caused by properties of the surface layers underlying the skin depth. © 2018 ESO., This work was supported by grant No. 2014/13/D/ST9/01818 from the National Science Centre, Poland. The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement No. 687378. V.K. was supported by the grant from the Slovak Research and Development Agency with number APVV-15-0458.
Published: 2017
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24. A new non-convex model of the binary asteroid 90 Antiope obtained with the SAGE modelling technique

Author: P. Wietrzycka, W. Dimitrow, Grzegorz Dudziński, Magdalena Polińska, Frédéric Vachier, R. Hirsch, M. Murawiecka, Agnieszka Kryszczyńska, P. Bartczak, F. Colas, A. Marciniak, G. Apostolovska, Jakub Nadolny, Toni Santana-Ros, and Joe Pollock
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010504 meteorology & atmospheric sciences, Scale (ratio), FOS: Physical sciences, Binary number, Astronomy and Astrophysics, Astrophysics, Density estimation, Computational Physics (physics.comp-ph), Lambda, Orbital period, 01 natural sciences, Occultation, Combinatorics, Photometry (optics), Space and Planetary Science, Asteroid, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, Physics - Computational Physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: We present a new non-convex model of the 90 Antiope binary asteroid, derived with a modified version of the SAGE (Shaping Asteroids with Genetic Evolution) method using disk-integrated photometry only. A new variant of the SAGE algorithm capable of deriving models of binary systems is described. The model of 90 Antiope confirms the system's pole solution ($\lambda=199^{\circ}$, $\beta=38^{\circ}$, $\sigma=\pm5^{\circ}$) and the orbital period ($16.505046 \pm 0.000005$ h). A comparison between the stellar occultation chords obtained during the 2011 occultation and the projected shape solution has been used to scale the model. The resulting scaled model allowed us to obtain the equivalent radii ($R_{1}=40.4\pm0.9$ km and $R_{2}=40.2\pm0.9$ km) and the distance between the two system components ($176\pm4$ km), leading to a total system mass of ($9.14\pm0.62$)$\cdot10^{17}$ kg. The non-convex shape description of the components permitted a refined calculation of the components' volumes, leading to a density estimation of $1.67\pm0.23$ g cm$^{-3}$. The intermediate-scale features of the model may also offer new clues on the components' origin and evolution.
Published: 2014

25. Statistical analysis of the ambiguities in the asteroid period determinations

Author: Grzegorz Dudziński, A. Marciniak, T. Kwiatkowski, P. Bartczak, and M. Butkiewicz-Bąk
Subjects: Rotation period, Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Gaussian, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Rotation, 01 natural sciences, symbols.namesake, Classical mechanics, Amplitude, Space and Planetary Science, Fourier analysis, Asteroid, 0103 physical sciences, symbols, Harmonic, SPHERES, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: Among asteroids there exist ambiguities in their rotation period determinations. They are due to incomplete coverage of the rotation, noise and/or aliases resulting from gaps between separate lightcurves. To help to remove such uncertainties, basic characteristic of the lightcurves resulting from constraints imposed by the asteroid shapes and geometries of observations should be identified. We simulated light variations of asteroids which shapes were modelled as Gaussian random spheres, with random orientations of spin vectors and phase angles changed every $5^\circ$ from $0^\circ$ to $65^\circ$. This produced 1.4 mln lightcurves. For each simulated lightcurve Fourier analysis has been made and the harmonic of the highest amplitude was recorded. From the statistical point of view, all lightcurves observed at phase angles $��< 30^\circ$, with peak-to-peak amplitudes $A>0.2$ mag are bimodal. Second most frequently dominating harmonic is the first one, with the 3rd harmonic following right after. For 1% of lightcurves with amplitudes $A < 0.1$ mag and phase angles $��< 40^\circ$ 4th harmonic dominates., 9 pages, 3 figures, 6 tables, accepted for publication in Monthly Notices of the Royal Astronomical Society
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26. Volume uncertainty assessment method of asteroid models from disc-integrated visual photometry

Author: Grzegorz Dudziński and P. Bartczak
Subjects: Rotation period, Physics, Earth and Planetary Astrophysics (astro-ph.EP), education.field_of_study, Solar System, 010308 nuclear & particles physics, Orientation (computer vision), Population, FOS: Physical sciences, Astronomy and Astrophysics, 01 natural sciences, Photometry (optics), Space and Planetary Science, Asteroid, 0103 physical sciences, Sensitivity (control systems), Statistical physics, Extreme value theory, education, 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: The need for more accurate asteroid models is perhaps secondary to the need to measure their quality. The uncertainties of models' parameters propagate to quantities like volume or density -- the most important and informative properties of asteroids -- affecting conclusions about their physical nature. Our knowledge on shapes and spins of small solar system bodies comes mostly from visual, disk-integrated photometry. In this work we present a method for asteroid model uncertainty assessment based on visual photometry (lightcurves and sparse-in-time absolute measurements) allowing the determination of realistic volume uncertainty, as well as spin axis orientation, rotational period and local surface features. The sensitivity analysis is conducted by creating clones of the nominal model and accepting the ones that fit the observations within a confidence level. The uncertainties of model parameters are extracted from the extreme values found in the accepted clone population. Creation of such population of clones enables the conversion of a deterministic asteroid model into stochastic one, and can be utilized to create observation predictions with error bars. The method was used to assess the uncertainties of fictitious test models and real targets, i.e. (21) Lutetia, (89) Julia, (243) Ida, (433) Eros and (162173) Ryugu. We conclude that volumes, and subsequently, densities of asteroids derived from lightcurve-based models likely have vastly understated uncertainties, the biggest source of which is the inability to establish the extent of the model along its spin axis.
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27. Small Bodies Near and Far (SBNAF): A benchmark study on physical and thermal properties of small bodies in the Solar System

Author: Cs. Kiss, Pablo Santos-Sanz, Victor Ali-Lagoa, E. Varga-Verebélyi, Dagmara Oszkiewicz, Grzegorz Dudziński, A. Takácsné Farkas, Rene Duffard, Róbert Szakáts, Estela Fernández-Valenzuela, M. Butkiewicz-Bąk, Nicolás Morales, Przemyslaw Bartczak, T. G. Müller, Gábor Marton, J. L. Ortiz, A. Marciniak, Toni Santana-Ros, and European Commission
Subjects: Atmospheric Science, Solar System, Radiation mechanisms: non-thermal, 010504 meteorology & atmospheric sciences, 7. Clean energy, 01 natural sciences, Space exploration, law.invention, Infrared: planetary systems, planetary systems [Submillimeter], law, Surface roughness, image processing [Techniques], Radar, 010303 astronomy & astrophysics, Techniques: astrometric, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Stellar occultations, general [Kuiper belt], Asteroids: general, Geophysics, thermal [Radiation mechanisms], Asteroid, Techniques: image processing, Techniques: radar astronomy, FOS: Physical sciences, Aerospace Engineering, planetary systems [Infrared], astrometric [Techniques], Submillimeter: planetary systems, 0103 physical sciences, Thermal, Adaptive optics, 0105 earth and related environmental sciences, Remote sensing, non-thermal [Radiation mechanisms], photometric [Techniques], Minor planets, Astronomy and Astrophysics, Inversion (meteorology), Radiation mechanisms: thermal, Astronomical data bases, 13. Climate action, Space and Planetary Science, General Earth and Planetary Sciences, Kuiper belt: general, radar astronomy [Techniques], general [Asteroids], Techniques: photometric, Astrophysics - Earth and Planetary Astrophysics
Abstract: The combination of visible and thermal data from the ground and astrophysics space missions is key to improving the scientific understanding of near-Earth, main-belt, trojans, centaurs, and trans-Neptunian objects. To get full information on a small sample of selected bodies we combine different methods and techniques: lightcurve inversion, stellar occultations, thermophysical modelling, radiometric methods, radar ranging and adaptive optics imaging. The SBNAF project will derive size, spin and shape, thermal inertia, surface roughness, and in some cases bulk densities and even internal structure and composition, for objects out to the most distant regions in the Solar System. The applications to objects with ground-truth information allows us to advance the techniques beyond the current state-of-the-art and to assess the limitations of each method. We present results from our project's first phase: the analysis of combined Herschel-KeplerK2 data and Herschel-occultation data for TNOs; synergy studies on large MBAs from combined high-quality visual and thermal data; establishment of well-known asteroids as celestial calibrators for far-infrared, sub-millimetre, and millimetre projects; first results on near-Earth asteroids properties from combined lightcurve, radar and thermal measurements, as well as the Hayabusa-2 mission target characterisation. We also introduce public web-services and tools for studies of small bodies in general. © 2017 COSPAR, The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement no. 687378.
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27 results on '"Grzegorz Dudziński"'

1. Gaia@home: Combining Gaia catalogue with the power of volunteer computing

2. Constraining the shape and density of binary asteroid (121) Hermione

3. (65) Cybele is the smallest asteroid at hydrostatic equilibrium, why?

4. VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis

5. An advanced multipole model for (216) Kleopatra triple system

6. Evidence for differentiation of the most primitive small bodies

7. Volume uncertainty of (7) Iris shape models from disc-resolved images

8. Binary asteroid (31) Euphrosyne: ice-rich and nearly spherical

9. Physical parameters of selected Gaia mass asteroids

10. The large trans-Neptunian object 2002 TC 302 from combined stellar occultation, photometry, and astrometry data

11. The violent collisional history of aqueously evolved (2) Pallas

12. Thermal properties of large main-belt asteroids observed by Herschel PACS

13. Asteroid (16) Psyche’s primordial shape: A possible Jacobi ellipsoid

14. The Europlanet Telescope Network: A global collaboration in support of planetary sciences

15. A basin-free spherical shape as an outcome of a giant impact on asteroid Hygiea

16. The shape of (7) Iris as evidence of an ancient large impact?

17. Closing the gap between Earth-based and interplanetary mission observations: Vesta seen by VLT/SPHERE

18. Optical observations of NEA 3200 Phaethon (1983 TB) during the 2017 apparition

19. The impact crater at the origin of the Julia family detected with VLT/SPHERE?

20. Shape models and physical properties of asteroids

21. The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation

22. Shaping asteroid models using genetic evolution (SAGE)

23. Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids

24. A new non-convex model of the binary asteroid 90 Antiope obtained with the SAGE modelling technique

25. Statistical analysis of the ambiguities in the asteroid period determinations

26. Volume uncertainty assessment method of asteroid models from disc-integrated visual photometry

27. Small Bodies Near and Far (SBNAF): A benchmark study on physical and thermal properties of small bodies in the Solar System

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27 results on '"Grzegorz Dudziński"'

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