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1. Comparing Apples with Apples: Robust Detection Limits for Exoplanet High-contrast Imaging in the Presence of Non-Gaussian Noise

Author

Markus J. Bonse, Emily O. Garvin, Timothy D. Gebhard, Felix A. Dannert, Faustine Cantalloube, Gabriele Cugno, Olivier Absil, Jean Hayoz, Julien Milli, Markus Kasper, and Sascha P. Quanz

Subjects
Astrostatistics, Bootstrap, Direct imaging, High angular resolution, Astronomy, QB1-991
Abstract

Over the past decade, hundreds of nights have been spent on the world’s largest telescopes to search for and directly detect new exoplanets using high-contrast imaging (HCI). Thereby, two scientific goals are of central interest: first, to study the characteristics of the underlying planet population and distinguish between different planet formation and evolution theories. Second, to find and characterize planets in our immediate solar neighborhood. Both goals heavily rely on the metric used to quantify planet detections and nondetections. Current standards often rely on several explicit or implicit assumptions about noise. For example, it is often assumed that the residual noise after data postprocessing is Gaussian. While being an inseparable part of the metric, these assumptions are rarely verified. This is problematic as any violation of these assumptions can lead to systematic biases. This makes it hard, if not impossible, to compare results across data sets or instruments with different noise characteristics. We revisit the fundamental question of how to quantify detection limits in HCI. We focus our analysis on the error budget resulting from violated assumptions. To this end, we propose a new metric based on bootstrapping that generalizes current standards to non-Gaussian noise. We apply our method to archival HCI data from the NACO instrument at the Very Large Telescope and derive detection limits for different types of noise. Our analysis shows that current standards tend to give detection limits that are about one magnitude too optimistic in the speckle-dominated regime. That is, HCI surveys may have excluded planets that can still exist.

Published
2023
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3. Auf Schritt und Tritt – Zur Bedeutung der visuellen Gangbildanalyse beim Hund

Author

Andreas Zohmann and Markus Kasper

Subjects
General Earth and Planetary Sciences, General Environmental Science
Abstract

Die Gangbildanalyse (GBA) ist ein wichtiges Werkzeug in der Befundung von Lahmheiten und der Erkennung von möglichen Schmerzzuständen. Sie liefert mit dem freien Auge die Möglichkeit, relativ rasch und effizient Auffälligkeiten zu erkennen und einzuordnen. Was sind die Voraussetzungen für eine gute Ganganalyse und wie geht man dabei am besten vor? Welche Rolle spielt die Gangart und wie erkennt und interpretiert man die häufigsten Störungsmuster? Nicht vergessen werden darf aber, dass die GBA nur einen Teil der Befundungen im Rahmen des orthopädisch-physiotherapeutischen Untersuchungsgangs darstellt.

Published
2022
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4. The GPII on Desktops in PCs OSs: Windows and GNOME

Author

Antúnez, Javier Hernández, Clark, Colin, Markus, Kasper, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Kobsa, Alfred, editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Weikum, Gerhard, editor, Stephanidis, Constantine, editor, and Antona, Margherita, editor

Published
2014
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5. Enabling Architecture: How the GPII Supports Inclusive Software Development

Author

Clark, Colin, Basman, Antranig, Bates, Simon, Markus, Kasper Galschiøt, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Kobsa, Alfred, editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Weikum, Gerhard, editor, Stephanidis, Constantine, editor, and Antona, Margherita, editor

Published
2014
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6. Lessons learned from the NEAR experiment and prospects for the upcoming mid-IR HCI instruments

Author

Prashant Pathak, Markus Kasper, Olivier Absil, Gilles Orban de Xivry, Ulli Käufl, Gerd Jakob, Ralf Siebenmorgen, Serban Leveratto, and Eric Pantin

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Earth and Planetary Astrophysics
Abstract

The mid-infrared (IR) regime is well suited to directly detect the thermal signatures of exoplanets in our solar neighborhood. The NEAR experiment: demonstration of high-contrast imaging (HCI) capability at ten microns, can reach sub-mJy detection sensitivity in a few hours of observation time, which is sufficient to detect a few Jupiter mass planets in nearby systems. One of the big limitations for HCI in the mid-IR is thermal sky-background. In this work, we show that precipitate water vapor (PWV) is the principal contributor to thermal sky background and science PSF quality. In the presence of high PWV, the HCI performance is significantly degraded in the background limited regime., Comment: 8 pages, 4 figures, conference proceedings (SPIE Astronomical telescopes and instrumentation 2022)

Published
2023
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7. The Evolving Global Public Inclusive Infrastructure (GPII)

Author

Vanderheiden, Gregg C., Treviranus, Jutta, Gemou, Maria, Bekiaris, Evangelos, Markus, Kasper, Clark, Colin, Basman, Antranig, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Stephanidis, Constantine, editor, and Antona, Margherita, editor

Published
2013
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20. Connecting SPHERE and CRIRES+ for the characterisation of young exoplanets at high spectral resolution: status update of VLT/HiRISE

Author

Arthur Vigan, Maxime Lopez, Mona El Morsy, Eduard R. Muslimov, Alexandre Viret, Gérard Zins, Graham J. Murray, Anne Costille, Gilles P. P. L. Otten, Ulf Seemann, Heiko Anwand-Heerwart, Kjetil Dohlen, Patrick Blanchard, José Garcia, Yannick Charles, Nicolas Tchoubaklian, Timothé Ely, Mark Phillips, Jérôme Paufique, Jean-Luc Beuzit, Mathis Houllé, Jean Costes, Raphaël Pourcelot, Isabelle Baraffe, Reinhold Dorn, Marc Jaquet, Markus Kasper, Ansgar Reiners, Alain Smette, Leonardo Blanco, Laurent Pallanca, Alexis Carlotti, Elodie Choquet, David Mouillet, Mamadou N'Diaye, 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), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Universidad ORT Uruguay, 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)-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, Université Côte d'Azur - École universitaire de recherche Odyssée - Sciences de la société et de l'environnement (UCA EUR SSE), and Université Côte d'Azur (UCA)

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), High-dispersion coronagraphy, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Characterisation, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Exoplanet, VLT, High-contrast imaging, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Spectroscopy, Astrophysics::Galaxy Astrophysics, High-spectral resolution, Astrophysics - Earth and Planetary Astrophysics
Abstract

New generation exoplanet imagers on large ground-based telescopes are highly optimised for the detection of young giant exoplanets in the near-infrared, but they are intrinsically limited for their characterisation by the low spectral resolution of their integral field spectrographs ($R, Submitted to SPIE Astronomical Telescopes + Instrumentation 2022, Adaptive Optics Systems VIII, Paper 12185-27

Published
2022
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21. GPU-based High-order adaptive OpticS Testbench

Author

Byron Engler, Markus Kasper, Paul Bristow, Cedric T. Heritier, Serban Leveratto, Christophe Verinaud, Miska Le Louarn, Jalo Nousiainen, Tapio Helin, Markus Bonse, Sascha Quanz, Adrian Glauser, Julien Bernard, Damien Gratadour, and Richard Clare

Published
2022
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23. Imaging nearby, habitable-zone planets with the Large Binocular Telescope Interferometer

Author

Steve Ertel, Kevin Wagner, Jarron Leisenring, Dániel Apai, Denis Defrère, Jeremy Dietrich, Joshua A. Eisner, Virginie Faramaz, William Hoffmann, Markus Kasper, Pete Klupar, Jared R. Males, Mark S. Marley, Hélène Rousseau, Stephanie Sallum, Eckhart Spalding, Jordan M. Stone, Pete Worden, Merand, A, Sallum, S, and Sanchez-Bermudez, J

Subjects
Technology, Science & Technology, high contrast, Physical Sciences, habitable zones, Optics, Astronomy & Astrophysics, interferometry, Infrared, Instruments & Instrumentation, exoplanets imaging, adaptive optics
Abstract

ispartof: OPTICAL AND INFRARED INTERFEROMETRY AND IMAGING VIII vol:12183 ispartof: Conference on Optical and Infrared Interferometry and Imaging VIII Part of SPIE Astronomical Telescopes and Instrumentation Conference location:CANADA, Montreal date:17 Jul - 22 Jul 2022 status: published

Published
2022
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24. Spondylosen und Organopathien – Wie hängen sie zusammen?

Author

Markus Kasper

Abstract

Spondylosen sind in der röntgenologischen Bildgebung der Brust-, Lenden- und Schwanzwirbelsäule einfach darstellbar. Schon aufgrund dieser röntgenologisch-pathologischen Prominenz können sie uns zu wichtigen Erkenntnissen über den Patienten führen. Um der klinischen Bedeutung der Spondylosen, ihrer Korrelation mit chronischen Organopathien, der praktischen Relevanz und der sich daraus ergebenden therapeutischen Optionen näher zu kommen, muss man ihre Ätiologie und Pathogenese verstanden haben.

Published
2020
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25. Want to improve your cascade 2-stage AO system? Turn it into a high-performance woofer-tweeter!

Author

Henri-François Raynaud, Caroline Kulcsár, Nelly Cerpa-Urra, and Markus Kasper

Abstract

2-stage cascade AO (CAO) systems enable to improve wavefront correction for high-contrast exoplanet imaging. However, 1st stage residuals entering the 2nd stage exhibit see-saw high-frequency oscillations. We propose a compensation procedure which turns the CAO into a woofer-tweeter configuration, thus significantly improving overall performance.

Published
2022
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26. Direct Imaging and Spectroscopy

Author

Sasha Hinkley, Markus Kasper, Arthur Vigan, Sylvestre Lacour, and Sascha P. Quanz

Subjects
Materials science, Nuclear magnetic resonance, Direct imaging, Spectroscopy
Published
2021
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27. Imaging low-mass planets within the habitable zones of nearby stars with ground-based mid-infrared imaging

Author

Jarron Leisenring, Daniel Apai, Markus Kasper, Olivier Guyon, Jordan Stone, Laird M. Close, Jared R. Males, Steve Ertel, Denis Defrere, Kevin Wagner, and Olivier Absil

Subjects
Very Large Telescope, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Large Binocular Telescope, Astrophysics::Cosmology and Extragalactic Astrophysics, Exoplanet, law.invention, Stars, Planet, law, Alpha Centauri, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Coronagraph, Circumstellar habitable zone, Astrophysics::Galaxy Astrophysics, Geology
Abstract

Giant exoplanets on 10-100 au orbits have been directly imaged around young stars. The peak of the thermal emission from these warm young planets is in the near-infrared (∼1-5 µm), whereas mature, temperate exoplanets (i.e., those within their stars’ habitable zones) radiate primarily in the mid-infrared (mid-IR: ∼10 µm). If the background noise in the mid-IR can be mitigated, then exoplanets with low masses–including rocky exoplanets–can potentially be imaged in very deep exposures. Here, we review the recent results of the Breakthrough Watch/New Earths in the Alpha Centauri Region (NEAR) program on the Very Large Telescope (VLT) in Chile. NEAR pioneered a ground-based mid-IR observing approach designed to push the capabilities for exoplanet imaging with a specific focus on the closest stellar system, α Centauri. NEAR combined several new optical technologies–including a mid-IR optimized coronagraph, adaptive optics system, and rapid chopping strategy to mitigate noise from the central star and thermal background within the habitable zone. We focus on the lessons of the VLT/NEAR campaign to improve future instrumentation specifically on strategies to improve noise mitigation through chopping. We also present the design and commissioning of the Large Binocular Telescope’s Exploratory Survey for Super-Earths Orbiting Nearby Stars (LESSONS), an experiment in the Northern hemisphere that is building on what was learned from NEAR to further push the sensitivity of mid-IR imaging. Finally, we briefly discuss some of the possibilities that mid-IR imaging will enable for exoplanet science.

Published
2021
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28. New mid-infrared imaging constraints on companions and protoplanetary disks around six young stars

Author

Eric Pantin, Hans Ulrich Käufl, M.E. van den Ancker, N. Oberg, R. van Boekel, Ralf Siebenmorgen, Inga Kamp, M. Kissler-Patig, Davide Fedele, Ch. Rab, Valentin D. Ivanov, L. B. F. M. Waters, Paulo A. Miles-Páez, Markus Kasper, Sascha P. Quanz, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), 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 Cité (UPCité), 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 de Paris (UP), and Astronomy

Subjects
Point spread function, Astronomy, FOS: Physical sciences, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Protoplanetary disk, 01 natural sciences, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010306 general physics, infrared: planetary systems, 010303 astronomy & astrophysics, infrared: stars, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Earth and Planetary Astrophysics (astro-ph.EP), Physics, protoplanetary disks, Astronomy and Astrophysics, Radius, methods: data analysis, Accretion (astrophysics), Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Spectral energy distribution, Astrophysics::Earth and Planetary Astrophysics, methods: observational, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract

Mid-infrared imaging traces the sub-micron and micron sized dust grains in protoplanetary disks and it offers constraints on the geometrical properties of the disks and potential companions, particularly if those companions have circumplanetary disks. We use the VISIR instrument and its upgrade NEAR on the VLT to take new mid-infrared images of five (pre-)transition disks and one circumstellar disk with proposed planets and obtain the deepest resolved mid-infrared observations to date in order to put new constraints on the sizes of the emitting regions of the disks and the presence of possible companions. We derotate and stack the data to find the disk properties. Where available we compare the data to ProDiMo (Protoplanetary Disk Model) radiation thermo-chemical models to achieve a deeper understanding of the underlying physical processes within the disks. We apply the circularised PSF subtraction method to find upper limits on the fluxes of possible companions and model companions with circumplanetary disks. We resolve three of the six disks and calculate position angles, inclinations and (upper limits to) sizes of emission regions in the disks, improving upper limits on two of the unresolved disks. In all cases the majority of the mid-IR emission comes from small inner disks or the hot inner rims of outer disks. We refine the existing ProDiMo HD 100546 model SED fit in the mid-IR by increasing the PAH abundance relative to the ISM, adopting coronene as the representative PAH, and increase the outer cavity radius to 22.3 AU. We produce flux estimates for putative planetary-mass companions and circumplanetary disks, ruling out the presence of planetary-mass companions with $L > 0.0028 L_{\odot}$ for $a > 180$ AU in the HD 100546 system. Upper limits of 0.5 mJy-30 mJy are obtained at 8 $��$m-12 $��$m for potential companions in the different disks., Accepted in A&A

Published
2021
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31. A high-contrast search for variability in HR 8799bc with VLT-SPHERE

Author

Markus Kasper, Arthur Vigan, Silvano Desidera, Daniel Apai, Kevin Wagner, C. Lazzoni, Matthew A. Kenworthy, Johanna M. Vos, Dino Mesa, Beth Biller, Mickael Bonnefoy, Raffaele Gratton, Alice Zurlo, Anne-Marie Lagrange, Laboratoire d'Astrophysique de Marseille (LAM), and 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)

Subjects
Astrophysics - instrumentation and methods for astrophysics, Star (game theory), media_common.quotation_subject, FOS: Physical sciences, Astrophysics, Astrophysics - Earth and planetary astrophysics, 01 natural sciences, Spectral line, 010309 optics, Infrared: planetary systems, Planet, 0103 physical sciences, Contrast (vision), Sensitivity (control systems), (Stars:) brown dwarfs, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, media_common, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Astronomy and Astrophysics, Position angle, Exoplanet, Planets and satellites: gaseous planets, Photometry (astronomy), [SDU]Sciences of the Universe [physics], Space and Planetary Science, astro-ph.EP, astro-ph.IM
Abstract

The planets HR8799bc display nearly identical colours and spectra as variable young exoplanet analogues such as VHS 1256-1257ABb and PSO J318.5-22, and are likely to be similarly variable. Here we present results from a 5-epoch SPHERE IRDIS broadband-$H$ search for variability in these two planets. HR 8799b aperture photometry and HR 8799bc negative simulated planet photometry share similar trends within uncertainties. Satellite spot lightcurves share the same trends as the planet lightcurves in the August 2018 epochs, but diverge in the October 2017 epochs. We consider $\Delta(mag)_{b} - \Delta(mag)_{c}$ to trace non-shared variations between the two planets, and rule out non-shared variability in $\Delta(mag)_{b} - \Delta(mag)_{c}$ to the 10-20$\%$ level over 4-5 hours. To quantify our sensitivity to variability, we simulate variable lightcurves by inserting and retrieving a suite of simulated planets at similar radii from the star as HR 8799bc, but offset in position angle. For HR 8799b, for periods $5\%$. For HR 8799c, our sensitivity is limited to variability $>25\%$ for similar periods., Comment: 41 pages, 24 figures, accepted to MNRAS

Published
2021
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32. Investigating three Sirius-like systems with SPHERE

Author

H. M. Schmid, Arthur Vigan, T. O. B. Schmidt, Mickael Bonnefoy, M. Keppler, E. Sissa, Markus Kasper, Antonio Garufi, S. Petrus, David Mouillet, E. L. Rickman, Sebastian Daemgen, M. Cudel, Alice Zurlo, J. L. Beuzit, Janis Hagelberg, Raffaele Gratton, Roxanne Ligi, J. Melendez, Anne-Lise Maire, François Ménard, Tomas Stolker, D. Gasparri, F. Rigal, Daniel Rouan, C. Soenke, E. Cascone, Matthias Samland, Silvano Desidera, R. Galicher, Christian Ginski, Gael Chauvin, Valentina D'Orazi, M. R. Mayer, A. Potier, A-M. Lagrange, Graeme Salter, Francois Wildi, H. Le Coroller, Maud Langlois, T. A. Pacheco, Henning Avenhaus, C. Desgrange, Beth Biller, C. Lazzoni, Mariangela Bonavita, Wolfgang Brandner, Markus Janson, Markus Feldt, S. Mazevet, N. Engler, Julien Girard, C. Perrot, Dino Mesa, J. Lannier, C. Fontanive, S. Hunziker, T. Moulin, S. Peretti, Joany Andreina Manjarres Ramos, M. Lombart, Riccardo Claudi, Philippe Delorme, A. Boccaletti, University of Arizona, 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Stockholm University, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Max Planck Institute for Radio Astronomy, 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)-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, European Southern Observatory (ESO), Universidad de Chile = University of Chile [Santiago] (UCHILE), University of Edinburgh, 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 Paris Cité (UPCité), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Chaire IPAG 'Entreprise Inclusive' (IPAG Business School), IPAG Business School, Observatoire de Paris, Université Paris sciences et lettres (PSL), Department of Biochemistry and Molecular Biology, Mayo Clinic, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Low Energy Astrophysics (API, FNWI), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Angular momentum, 530 Physics, Sirius, CD-56 7708, HD 114174, FOS: Physical sciences, Individual, Astrophysics, 01 natural sciences, Nucleosynthesis, 0103 physical sciences, Asymptotic giant branch, Solar and Stellar Astrophysics, Abundances, General, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, 520 Astronomy, Binaries, White dwarf, Astronomy and Astrophysics, HD 2133, Stars, White Dwarfs, Orbit, Photometry (astronomy), Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Sirius-like systems are wide binaries composed of a white dwarf (WD) and a companion of a spectral type earlier than M0. The WD progenitor evolves in isolation, but its wind during the AGB phase pollutes the companion surface and transfers some angular momentum. Within SHINE survey that uses SPHERE at the VLT, we acquired images of HD2133, HD114174, and CD-567708 and combined this data with high resolution spectra of the primaries, TESS, and literature data. We performed accurate abundance analyses for the MS. We found brighter J and K magnitudes for HD114174B than obtained previously and extended the photometry down to 0.95 micron. Our new data indicate a higher temperature and then shorter cooling age (5.57+/-0.02 Gyr) and larger mass (0.75+/-0.03 Mo) for this WD than previously assumed. This solved the discrepancy previously found with the age of the MS star. The two other WDs are less massive, indicating progenitors of ~1.3 Mo and 1.5-1.8 Mo for HD2133B and CD-56 7708B, respectively. We were able to derive constraints on the orbit for HD114174 and CD-56 7708. The composition of the MS stars agrees fairly well with expectations from pollution by the AGB progenitors of the WDs: HD2133A has a small enrichment of n-capture elements, which is as expected for pollution by an AGB star with a mass 3.0 Mo. On the other hand, none of these stars show the excesses of C that are expected to go along with those of n-capture elements. This might be related to the fact that these stars are at the edges of the mass range where we expect nucleosynthesis related to thermal pulses., Accepted on Astronomy and Astrophysics. 19 pages, 15 figures

Published
2021
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33. Overview on wavefront corrector technologies for astronomy and solar adaptive optics systems

Author

P. Y. Madec, Markus Kasper, and Stefan Ströbele

Subjects
Wavefront, Computer science, Key (cryptography), Electronic engineering, Adaptive optics systems, Adaptive optics, Deformable mirror
Abstract

By now Adaptive optics systems are used at nearly all large telescopes. Over the past years not only the number of applications increased but as well the correction order and specialization have evolved. One key element following and sometimes driving the development of adaptive optics is the wavefront corrector. The construction and development of the ELTs and other new facilities pushed the development of new and much larger deformable mirrors. An overview of the available and newly developed technologies with their key performances is presented.

Published
2020
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34. Retraction

Author

Kevin Wagner, Dániel Apai, Markus Kasper, Kaitlin Kratter, Melissa McClure, Massimo Robberto, and Jean-Luc Beuzit

Subjects
Multidisciplinary
Published
2022
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35. Direct Imaging Discovery of a Young Brown Dwarf Companion to an A2V Star

Author

Massimo Robberto, Kevin Wagner, Daniel Apai, Markus Kasper, Melissa McClure, Thayne Currie, and Low Energy Astrophysics (API, FNWI)

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010504 meteorology & atmospheric sciences, Brown dwarf, FOS: Physical sciences, Astronomy and Astrophysics, Astrometry, Astrophysics, Stellar classification, 01 natural sciences, Accretion (astrophysics), Exoplanet, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Planet, 0103 physical sciences, 010303 astronomy & astrophysics, Circumstellar habitable zone, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the discovery and spectroscopy of HIP 75056Ab, a companion directly imaged at a very small separation of 0.125 arcsec to an A2V star in the Scorpius-Centaurus OB2 association. Our observations utilized VLT/SPHERE between 2015$-$2019, enabling low-resolution spectroscopy (0.95$-$1.65 $\mu m$), dual-band imaging (2.1$-$2.25 $\mu m$), and relative astrometry over a four-year baseline. HIP 75056Ab is consistent with spectral types in the range of M6$-$L2 and $T_{\rm eff}\sim$ 2000$-$2600 K. A comparison of the companion's brightness to evolutionary tracks suggests a mass of $\sim$20$-$30 M$_{Jup}$. The astrometric measurements are consistent with an orbital semi-major axis of $\sim$15$-$45 au and an inclination close to face-on (i$\lesssim$35$^o$). In this range of mass and orbital separation, HIP 75056Ab is likely at the low-mass end of the distribution of companions formed via disk instability, although a formation of the companion via core accretion cannot be excluded. The orbital constraints are consistent with the modest eccentricity values predicted by disk instability, a scenario that can be confirmed by further astrometric monitoring. HIP 75056Ab may be utilized as a low-mass atmospheric comparison to older, higher-mass brown dwarfs, and also to young giant planets. Finally, the detection of HIP 75056Ab at 0.125 arcsec represents a milestone in detecting low-mass companions at separations corresponding to the habitable zones of nearby Sun-like stars., Comment: Accepted for publication in ApJL

Published
2020

36. ALMA chemical survey of disk-outflow sources in Taurus (ALMA-DOT)

Author

Davide Fedele, Dominique Segura-Cox, Jaime E. Pineda, Francesca Bacciotti, Antonio Garufi, Linda Podio, M. Vander Donckt, Leonardo Testi, E. Humphreys, Markus Kasper, Claudio Codella, and S. Mercimek

Subjects
Physics, Chemical content, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Astrophysics - Astrophysics of Galaxies, Accretion (astrophysics), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Mass content, Astrophysics of Galaxies (astro-ph.GA), Outflow, Mass budget, Solar and Stellar Astrophysics (astro-ph.SR), Line (formation)
Abstract

Planet-forming disks are not isolated systems. Their interaction with the surrounding medium affects their mass budget and chemical content. In the context of the ALMA-DOT program, we obtained high-resolution maps of assorted lines from six disks that are still partly embedded in their natal envelope. In this work, we examine the SO and SO$_2$ emission that is detected from four sources: DG Tau, HL Tau, IRAS 04302+2247, and T Tau. The comparison with CO, HCO$^+$, and CS maps reveals that the SO and SO$_2$ emission originates at the intersection between extended streamers and the planet-forming disk. Two targets, DG Tau and HL Tau, offers clear cases of inflowing material inducing an accretion shock on the disk material. The measured rotational temperatures and radial velocities are consistent with this view. In contrast to younger Class 0 sources, these shocks are confined to the specific disk region impacted by the streamer. In HL Tau, the known accreting streamer induces a shock in the disk outskirt, and the released SO and SO$_2$ molecules spiral toward the star in a few hundreds years. These results suggest that shocks induced by late accreting material may be common in the disks of young star-forming regions with possible consequences on the chemical composition and mass content of the disk. They also highlight the importance of SO and SO$_2$ line observations to probe accretion shocks from a larger sample., 18 pages, 13 figures, accepted by A$\&$A

Published
2022
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38. Einsatz von Telemedizin in einem berufsgenossenschaftlichen Klinikum

Author

Markus Kasper and Markus Kasper

Abstract

Masterarbeit aus dem Jahr 2021 im Fachbereich Gesundheit - Digital Health Management, Note: 1,3, Hochschule Fresenius Idstein, Sprache: Deutsch, Abstract: Diese Arbeit beschäftigt sich mit dem Einsatz von Telemedizin in einem berufsgenossenschaftlichen Klinikum unter besonderer Berücksichtigung von Videosprechstunden. Mit Beginn der Covid-19 Pandemie stellte sich für die BG Kliniken die Frage, wie die medizinische Versorgung von Patientinnen und Patienten durch telemedizinische Verfahren unter besonderer Berücksichtigung des Einsatzes von Videosprechstunden sichergestellt werden kann. Ziel war es dabei, persönliche Kontakte zu verringern und das Ausbreiten des Virus zu minimieren. Mithilfe von qualitativen Interviews von Expertinnen und Experten des ärztlichen Personals wurde daraufhin untersucht, welche Auswirkungen die Covid-19 Pandemie auf die Nutzung von Videosprechstunden im ambulanten und stationären Sektor des Klinikums als überregionales Traumazentrum hat. Im Ergebnis bestätigte sich, dass die Nutzung der Videosprechstunde ausschließlich in einzelnen Fachgebieten im ambulanten Sektor erweitert wurde. Der Einsatz der Videosprechstunde erfolgte in der Rehabilitation und der technischen Orthopädie, der Klinik für Schmerzmedizin sowie der zentralen Notaufnahme der Orthopädie und Unfallchirurgie. Dies führte allerdings lediglich nach dem ersten Lockdown zu einer kurzfristig erhöhten Nachfrage und reduzierte sich im weiteren Verlauf fast gegen null. Als Hinderungsgründe für den Einsatz wurden neben den technischen Voraussetzungen auch die fehlende Ausstattung mit geeigneten Endgeräten genannt. Darüber hinaus wird im Bereich der Psychotraumatologie bei den überwiegend schwerst traumatisierten Menschen mit dem Einsatz von Körpertechniken eine sofortige persönliche Betreuung notwendig, welche sich per Videosprechstunde nicht durchführen lässt. Wichtig wird es für die BG Kliniken daher, sukzessiv den Digitalisierungsgrad über die geförderten Vorhaben aus dem Krankenhauszukunftsgesetz zu erhöhen, um telemedizinische Verfahren, wie die Videosprechstunde oder digitale Gesundheitsanwendungen, in den Klinikalltag zu integrieren. Unabhängig von deren Finanzierung ist es wichtig für die überörtlichen Traumazentren, die Konkurrenzfähigkeit der BG Kliniken im digitalen Wandel der Gesellschaft gegenüber anderen Krankenhäusern zu erhöhen. Vorteilhaft wäre es dabei, die bereits eingeleiteten digitalen Maßnahmen auszubauen und bei einer Digitalisierungsstrategie die patientenzentrierte Sichtweise zu berücksichtigen.

Published
2022

39. Constraints on the nearby exoplanet ϵ Indi Ab from deep near- and mid-infrared imaging limits

Author

Gayathri Viswanath, Markus Janson, Carl-Henrik Dahlqvist, Dominique Petit dit de la Roche, Matthias Samland, Julien Girard, Prashant Pathak, Markus Kasper, Fabo Feng, Michael Meyer, Anna Boehle, Sascha P. Quanz, Hugh R. A. Jones, Olivier Absil, Wolfgang Brandner, Anne-Lise Maire, Ralf Siebenmorgen, Michael Sterzik, and Eric Pantin

Subjects
Physics, 010504 meteorology & atmospheric sciences, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Mid infrared, Astronomy and Astrophysics, Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, Exoplanet, 0105 earth and related environmental sciences
Abstract

The past decade has seen increasing efforts in detecting and characterising exoplanets using high-contrast imaging in the near- and mid-infrared, which is the optimal wavelength domain for studying old, cold planets. In this work, we present deep adaptive optics imaging observations of the nearby Sun-like star ϵ Ind A with the NaCo (L′) and NEAR (10–12.5 microns) instruments at VLT in an attempt to directly detect its planetary companion, whose presence has been indicated from radial velocity (RV) and astrometric trends. We derive brightness limits from the non-detection of the companion with both instruments and interpret the corresponding sensitivity in mass based on both cloudy and cloud-free atmospheric and evolutionary models. For an assumed age of 5 Gyr for the system, we get detectable mass limits as low as 4.4 MJ in NaCo L′ and 8.2 MJ in NEAR bands at 1.5′′ from the central star. If the age assumed is 1 Gyr, we reach even lower mass limits of 1.7 MJ in NaCo L′ and 3.5 MJ in NEAR bands at the same separation. However, based on the dynamical mass estimate (3.25 MJ) and ephemerides from astrometry and RV, we find that the non-detection of the planet in these observations puts a constraint of 2 Gyr on the lower age limit of the system. NaCo offers the highest sensitivity to the planetary companion in these observations, but the combination with the NEAR wavelength range adds a considerable degree of robustness against uncertainties in the atmospheric models. This underlines the benefits of including a broad set of wavelengths for the detection and characterisation of exoplanets in direct imaging studies.

Published
2021
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40. Adaptive optics control using model-based reinforcement learning

Author

Tapio Helin, Chang Rajani, Jalo Nousiainen, Markus Kasper, and Department of Computer Science

Subjects
PREDICTION, Computer science, Aperture, FOS: Physical sciences, 114 Physical sciences, 01 natural sciences, Deformable mirror, 010309 optics, Optics, Control theory, 0103 physical sciences, Reinforcement learning, RECONSTRUCTION, Adaptive optics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Artificial neural network, Computer simulation, business.industry, 113 Computer and information sciences, Atomic and Molecular Physics, and Optics, Stochastic gradient descent, Control system, NEURAL-NETWORKS, Astrophysics - Instrumentation and Methods for Astrophysics, business, SYSTEM
Abstract

Reinforcement Learning (RL) presents a new approach for controlling Adaptive Optics (AO) systems for Astronomy. It promises to effectively cope with some aspects often hampering AO performance such as temporal delay or calibration errors. We formulate the AO control loop as a model-based RL problem (MBRL) and apply it in numerical simulations to a simple Shack-Hartmann Sensor (SHS) based AO system with 24 resolution elements across the aperture. The simulations show that MBRL controlled AO predicts the temporal evolution of turbulence and adjusts to mis-registration between deformable mirror and SHS which is a typical calibration issue in AO. The method learns continuously on timescales of some seconds and is therefore capable of automatically adjusting to changing conditions., Accepted for publication in Optics Express

Published
2021
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41. Direct characterization of young giant exoplanets at high spectral resolution by coupling SPHERE and CRIRES+

Author

M. El Morsy, P. Cristofari, Jean-François Sauvage, M. Houllé, Anne Costille, C. Mordasini, Ulf Seemann, M. Lopez, R. Pourcelot, J. L. Beuzit, Ansgar Reiners, Gilles Otten, Reinhold J. Dorn, Y. Charles, Mark W. Phillips, Mamadou N'Diaye, Kjetil Dohlen, Arthur Vigan, Markus Kasper, Elodie Choquet, Isabelle Baraffe, Eduard Muslimov, 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), NASA GODDARD INSTITUTE FOR SPACE STUDIES NEW YORK USA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Physikalisches Institut [Bern], Universität Bern [Bern], Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-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), 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)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern] (UNIBE), and N'Diaye, Mamadou

Subjects
530 Physics, FOS: Physical sciences, Astrophysics, 01 natural sciences, [PHYS] Physics [physics], law.invention, [SDU] Sciences of the Universe [physics], 010309 optics, Apparent magnitude, instrumentation: high angular resolution, law, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Spectral resolution, infrared: planetary systems, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Coronagraph, Spectrograph, Astrophysics::Galaxy Astrophysics, instrumentation: spectrographs, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], Physics, Very Large Telescope, 520 Astronomy, Astronomy and Astrophysics, 620 Engineering, Exoplanet, Stars, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract

Studies of atmospheres of directly imaged exoplanets with high-resolution spectrographs have shown that their characterization is predominantly limited by noise on the stellar halo at the location of the studied exoplanet. An instrumental combination of high-contrast imaging and high spectral resolution that suppresses this noise and resolves the spectral lines can therefore yield higher quality spectra. We study the performance of the proposed HiRISE fiber coupling between the SPHERE and CRIRES+ at the VLT for spectral characterization of directly imaged planets. Using end-to-end simulations of HiRISE we determine the S/N of the detection of molecular species for known exoplanets in $H$ and $K$ bands, and compare them to CRIRES+. We investigate the ultimate detection limits of HiRISE as a function of stellar magnitude, and we quantify the impact of different coronagraphs and of the system transmission. We find that HiRISE largely outperforms CRIRES+ for companions around bright hosts like $��$ Pic or 51 Eri. For an $H=3.5$ host, we observe a gain of a factor of up to 16 in observing time with HiRISE to reach the same S/N on a companion at 200 mas. More generally, HiRISE provides better performance than CRIRES+ in two-hour integration times between 50-350 mas for hosts with $H, 21 pages, 17 figures. 2 tables. Originally accepted for publication in A&A. Revised version after error in sky background was discovered (too high) and corrected in proofing stage. Revisions made in Abstract, Sections 3-6 and Figures 6-12,C1,C2 that address the changes in performance. Resubmitted to A&A

Published
2021
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42. Direct imaging discovery of a Jovian exoplanet within a triple-star system

Author

Markus Kasper, Kaitlin M. Kratter, Kevin Wagner, M. K. McClure, Daniel Apai, Massimo Robberto, and Jean-Luc Beuzit

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, Multidisciplinary, Triple system, FOS: Physical sciences, Astronomy, Binary number, Astrophysics, 01 natural sciences, Exoplanet, Jovian, 010309 optics, Jupiter, Orbit, Astrophysics - Solar and Stellar Astrophysics, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Spectroscopy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract

Spying a planet in a triple-star system Thousands of extrasolar planets are now known, but only a handful have been detected in direct images. Wagner et al. used sophisticated adaptive optics to discover a planet in images of the triple-star system HD 131399 and to take a spectrum of its atmosphere (see the Perspective by Oppenheimer). The planet, about four times the mass of Jupiter, orbits around one star in the system while the other two stars move farther out. This unusual arrangement is puzzling: The planet's orbit may be stable, but it is unclear how it could have formed or migrated there. The results will be used to refine theories of planet formation. Science , this issue p. 673 ; see also p. 644

Published
2016
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43. SPHERE / ZIMPOL high resolution polarimetric imager. I. System overview, PSF parameters, coronagraphy, and polarimetry

Author

Carsten Dominik, Anthony Boccaletti, François Ménard, Riccardo Claudi, Mark Downing, Hans Martin Schmid, S. Antoniucci, Kjetil Dohlen, A. van Duin, J.-L. Beuzit, E. Sissa, Christoph U. Keller, Markus Kasper, Thierry Fusco, Sascha P. Quanz, Ronald Roelfsema, E. Mulder, Ralf Siebenmorgen, Arthur Vigan, N. Engler, David Mouillet, Marcos Suarez, Julien Girard, Eric Lagadec, H. Hanenburg, M. de Haan, Norbert Hubin, G. Chauvin, Raffaele Gratton, Johan Pragt, Eddy Elswijk, Patrice Martinez, D. Gisler, Andrea Baruffolo, Marcel Carbillet, Stéphane Udry, Jean-François Sauvage, A. Bazzon, F. Rigal, Christian Ginski, Franco Joos, Linda Podio, Anne Costille, Bernardo Salasnich, Maud Langlois, Silvano Desidera, Frans Snik, Francois Wildi, A. Pavlov, S. Hunziker, Lyu Abe, Henning Avenhaus, M. Feldt, J.-B. Daban, R. G. van Holstein, Pierre Baudoz, M. Schuil, Julien Milli, Thomas Henning, Christian Thalmann, Massimo Turatto, Pascal Puget, Low Energy Astrophysics (API, FNWI), ITA, FRA, DEU, CHL, NLD, CHE, Institute for Astronomy, Department of Physics, ETH Zürich, Netherlands Institute for Radio Astronomy (ASTRON), 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)-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, European Southern Observatory, Istituto Ricerche Solari Locarno, Astronomical Institute Anton Pannekoek, University of Amsterdam, 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), Haute résolution angulaire en astrophysique, 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)-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 Paris Cité (UPCité), Leiden Observatory, 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), INAF-Osservatorio Astronomico di Roma (INAF-OAR), Max-Planck-Institut für Astronomie (MPIA), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), 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), Laboratoire Franco-Chilien d'Astronomie, UMI 3386, European Southern Observatory (ESO), ONERA, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Firenze, Italy, and Geneva Observatory, University of Geneva, Chemin des Mailettes 51, 1290, Versoix, Switzerland

Subjects
Brightness, Polarimetry, FOS: Physical sciences, instrumentation: adaptive optics, 01 natural sciences, Encircled energy, circumstellar matter, 010309 optics, Optics, instrumentation: high angular resolution, 0103 physical sciences, Surface brightness, 010303 astronomy & astrophysics, Image resolution, planetary systems, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, Mira variable, business.industry, instrumentation: detectors, instrumentation: polarimeters, Astronomy and Astrophysics, Polarimeter, Space and Planetary Science, Circumstellar dust, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We describe the Zurich Imaging Polarimeter (ZIMPOL), the visual focal plane subsystem of the SPHERE "VLT planet finder", which pushes the limits of current AO systems to shorter wavelengths, higher spatial resolution, and much improved polarimetric performance. We provide new benchmarks for the performance of high contrast instruments, in particular for polarimetric differential imaging. We have analyzed SPHERE/ZIMPOL point spread functions and measure the peak surface brightness, the encircled energy, and the full width half maximum (FWHM) for different wavelengths, atmospheric conditions, star brightness, and instrument modes. Coronagraphic images are described and analized and the performance for different coronagraphs is compared with tests for the binary alpha Hyi with a separation of 92 mas and a contrast of 6 mag. For the polarimetric mode we made the instrument calibrations using zero polarization and high polarization standard stars and here we give a recipe for the absolute calibration of polarimetric data. The data show a small, 38 pages with 33 figurs, accepted for publication in Astron. Astrophys

Published
2018

44. Simulation of a cascaded adaptive optic system for high contrast imaging

Author

Henri-François Raynaud, Markus Kasper, Caroline Kulcsár, Miska Le Louarn, and Nelly Natalia Cerpa Urra

Subjects
Software, Computer simulation, Computer science, business.industry, Electronic engineering, Systems architecture, Retrofitting, Contrast (statistics), Stage (hydrology), Degrees of freedom (mechanics), business, Adaptive optics
Abstract

Higher contrast on images using Adaptive Optics (AO) systems is a topic on demand to be develop for high contrast imaging, especially on objects with small angular separations mixed with low entrance flux. Is for this, that a new system architecture is presented on this proceeding, where an already existing low order system (the 1st stage) is retrofitting a high order, fast system (the 2nd stage). The benefits of such a design is to minimize interventions in the hardware and software of the existing system, while increasing the number of degrees of freedom and speed of the combined system. The 1st stage is completely independent, and does not see the corrections done by the 2nd stage. We present here the analytical formulation and simulations results of such a system. First the system is described and the methodology is presented, where an analytical model was used to roughly determine system parameters for the 1st stage and 2nd stage, and then, a numerical simulation is performed using Octopus for verification.

Published
2018
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45. Magellan Adaptive Optics Imaging of PDS 70: Measuring the Mass Accretion Rate of a Young Giant Planet within a Gapped Disk

Author

Melissa McClure, Thomas Henning, Katie M. Morzinski, Jared R. Males, Katherine B. Follette, Daniel Apai, Joseph Long, Ya-Lin Wu, A. Gibbs, Kevin Wagner, André Müller, Markus Kasper, Miriam Keppler, Laird M. Close, and Low Energy Astrophysics (API, FNWI)

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, High contrast, Giant planet, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Exoplanet, 010309 optics, Accretion rate, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Adaptive optics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Positive probability, Astrophysics - Earth and Planetary Astrophysics
Abstract

PDS 70b is a recently discovered and directly imaged exoplanet within the wide ($\gtrsim$40 au) cavity around PDS 70 (Keppler et al. 2018, M\"uller et al. 2018). Ongoing accretion onto the central star suggests that accretion onto PDS 70b may also be ongoing. We present the first high contrast images at H$\alpha$ (656 nm) and nearby continuum (643 nm) of PDS 70 utilizing the MagAO system. The combination of these filters allows for the accretion rate of the young planet to be inferred, as hot infalling hydrogen gas will emit strongly at H$\alpha$ over the optical continuum. We detected a source in H$\alpha$ at the position of PDS 70b on two sequential nights in May 2018, for which we establish a false positive probability of $, Comment: 6 pages, 5 figures, accepted to ApJL

Published
2018

46. Around the world: status and prospects with the infrared vortex coronagraph (Conference Presentation)

Author

Maddalena Reggiani, Matthew A. Kenworthy, Julien Milli, Valentin Christiaens, Eric Pantin, Brunella Carlomagno, Keith Matthews, Eugene Serabyn, Aïssa Jolivet, Julien Girard, Dimitri Mawet, Serge Habraken, Hans-Ulrich Käufl, Denis Defrere, Ernesto Vargas Catalan, Jean Surdej, Elsa Huby, Pierre Piron, Mikael Karlsson, Markus Kasper, Olivier Absil, Philip M. Hinz, A. J. Eldorado Riggs, Carlos Gomez Gonzalez, Gilles Orban de Xivry, and Christian Delacroix

Subjects
biology, Computer science, Astronomy, First light, biology.organism_classification, Exoplanet, law.invention, Upgrade, law, Observatory, Alpha Centauri, Circumstellar habitable zone, Coronagraph, Eris
Abstract

Since its first light at the VLT in 2012, the Annular Groove Phase Mask (AGPM) has been used to implement vortex coronagraphy into AO-assisted infrared cameras at two additional world-leading observatories: the Keck Observatory and the LBT. In this paper, we review the status of these endeavors, and briefly highlight the main scientific results obtained so far. We explore the performance of the AGPM vortex coronagraph as a function of instrumental constraints, and identify the main limitations to the sensitivity to faint, off-axis companions in high-contrast imaging. These limitations include the AGPM itself, non-common path aberrations, as well as the data processing pipeline; we briefly describe our on-going efforts to further improve these various aspects. Based on the lessons learned from the first five years of on-sky exploitation of the AGPM, we are now preparing its implementation in a new generation of high-contrast imaging instruments. We detail the specificities of these instruments, and how they will enable the full potential of vortex coronagraphy to be unleashed in the future. In particular, we explain how the AGPM will be used to hunt for planets in the habitable zone of alpha Centauri A and B with a refurbished, AO-assisted version of the VISIR mid-infrared camera at the VLT (aka the NEAR project), and how this project paves the way towards mid-infrared coronagraphy on the ELT with the METIS instrument. We also discuss future LM-band applications of the AGPM with VLT/ERIS, ELT/METIS, and with a proposed upgrade of Keck/NIRC2, as well as future applications at shorter wavelengths, such as a possible upgrade of VLT/SPHERE with a K-band AGPM.

Published
2018
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47. NEAR: New Earths in the Alpha Cen Region (bringing VISIR as a 'visiting instrument' to ESO-VLT-UT4)

Author

Markus Kasper, Serban Leveratto, Brunella Carlomagno, Olivier Guyon, Gérard Zins, Olivier Absil, Dirk Kampf, Sven Gutruf, M. Riquelme, Eric Pantin, Kjetil Dohlen, Hans-Ulrich Käufl, Peter Klupar, Garreth Ruane, Dimitri Mawet, Ralf Siebenmorgen, Gerd Jakob, Eloy Fuenteseca, Nancy Ageorges, Mikael Karlsson, Arnd Reutlinger, Robin Arsenault, Michael Sterzik, Evans, Christopher J., Simard, Luc, and Takami, Hideki

Subjects
Lyot stop, Very Large Telescope, 010308 nuclear & particles physics, Computer science, Astronomy, 01 natural sciences, law.invention, Telescope, Observatory, Planet, law, 0103 physical sciences, Adaptive optics, 010303 astronomy & astrophysics, Coronagraph, Radio astronomy
Abstract

By adding a dedicated coronagraph, ESO in collaboration with the Breakthrough Initiatives, modifies the Very Large Telescope mid-IR imager (VISIR) to further boost the high dynamic range imaging capability this instru- ment has. After the VISIR upgrade in 2012, where coronagraphic masks were first added to VISIR, it became evident that coronagraphy at a ground-based 8m-class telescope critically needs adaptive optics, even at wavelengths as long as 10μm. For VISIR, a work-horse observatory facility instrument in normal operations, this is ”easiest” achieved by bringing VISIR as a visiting instrument to the ESO-VLT-UT4 having an adaptive M2. This “visit” enables a meaningful search for Earth-like planets in the habitable zone around both α-Cen1,2. Meaningful here means, achieving a contrast of ≈ 10^(-6) within ≈ 0.8arcsec from the star while maintaining basically the normal sensitivity of VISIR. This should allow to detect a planet twice the diameter of Earth. Key components will be a diffractive coronagraphic mask, the annular groove phase mask (AGPM), optimized for the most sensitive spectral band-pass in the N-band, complemented by a sophisticated apodizer at the level of the Lyot stop. For VISIR noise filtering based on fast chopping is required. A novel internal chopper system will be integrated into the cryostat. This chopper is based on the standard technique from early radio astronomy, conceived by the microwave pioneer Robert Dicke in 1946, which was instrumental for the discovery of the 3K radio background.

Published
2018

48. Discovery of a brown dwarf companion to the star HIP 64892

Author

Jacopo Antichi, L. Weber, E. Sissa, Johan Olofsson, H. Le Coroller, Markus Kasper, Damien Ségransan, Alain Roux, T. Buey, Alice Zurlo, Cyril Petit, Alain Delboulbé, Andrea Baruffolo, Thomas Henning, Arnaud Sevin, P. Blanchard, Ronald Roelfsema, Daniela Fantinel, Alain Origne, R. Ligi, Anne Costille, M. Carle, Kjetil Dohlen, François Ménard, Bernardo Salasnich, Maud Langlois, Pierre Baudoz, V. De Caprio, Enrico Giro, D. Maurel, Lyu Abe, Markus Janson, O. Möller-Nilsson, Raffaele Gratton, Jean-Luc Beuzit, Riccardo Claudi, Beth Biller, Eric Stadler, Valentina D'Orazi, Massimo Turatto, Marc Jaquet, Joshua E. Schlieder, Pascal Puget, Taisiya Kopytova, Yves Magnard, Arthur Vigan, C. Soenke, Anthony Cheetham, Anne-Lise Maire, Patrice Martinez, D. Le Mignant, Gérard Rousset, A. Pavlov, Norbert Hubin, M. Keppler, Anne-Marie Lagrange, Emmanuel Hugot, Eric Lagadec, Hubert Klahr, Daniel Rouan, Dino Mesa, Michael Meyer, Thierry Fusco, Janis Hagelberg, Markus Feldt, Philippe Feautrier, Joany Andreina Manjarres Ramos, Quentin Kral, M. Llored, E. Cascone, Marcel Carbillet, S. Rochat, T. O. B. Schmidt, Mickael Bonnefoy, T. Moulin, S. Peretti, P. Rabou, David Mouillet, L. Gluck, J. Pragt, Gael Chauvin, F. Madec, Jean-François Sauvage, Francois Wildi, C. Mordasini, Denis Perret, Carsten Dominik, Anthony Boccaletti, F. Rigal, Marcos Suarez, Stéphane Udry, Silvano Desidera, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - 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), 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), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Universidad de Chile, Universidad de Valparaiso [Chile], Stockholm University, University of Edinburgh, Instituto de Astronomia y ciencias Planetarias de Atacama (INCT), Universidad de Atacama, University of Cambridge [UK] (CAM), NASA Goddard Space Flight Center (GSFC), University of Bern, Universidad Diego Portales [Santiago] (UDP), Institute for Particle Physics and Astrophysics [ETH Zürich] (IPA), Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Mathematics - University of Michigan, University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Arizona State University [Tempe] (ASU), Ural Federal University [Ekaterinburg] (UrFU), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), INAF - Osservatorio Astronomico di Capodimonte (OAC), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), European Southern Observatory (ESO), NOVA Optical Infrared Instrumentation Group, European Southern Observatory [Santiago] (ESO), Université de Genève = University of Geneva (UNIGE), 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)-Centre National de la Recherche Scientifique (CNRS), Universidad de Chile = University of Chile [Santiago] (UCHILE), 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 d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), 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), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Low Energy Astrophysics (API, FNWI), Department of Physical Geography and Ecosystem Science [Lund], Lund University [Lund], Institute for Astronomy [Edinburgh] (IfA), Geneva Observatory, Department of Biochemistry and Molecular Biology, Mayo Clinic, Observatoire de Paris, Université Paris sciences et lettres (PSL), 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
[PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], INDIVIDUAL: HIP 64892 [STARS], HIGH ANGULAR RESOLUTIONS [TECHNIQUES], 530 Physics, Astrophysics::High Energy Astrophysical Phenomena, BROWN DWARFS, FOS: Physical sciences, Library science, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, DETECTIONS [PLANETS AND SATELLITES], OPTIQUE ADAPTATIVE, 01 natural sciences, Techniques: high angular resolution, VLT, 0103 physical sciences, DETECTION [PLANETS AND SATELLITES], Astrophysics::Solar and Stellar Astrophysics, European commission, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Stars: brown dwarfs individual: HIP 64892, HIGH ANGULAR RESOLUTION [TECHNIQUES], Earth and Planetary Astrophysics (astro-ph.EP), Physics, ASTRONOMIE, INDIVIDUAL [STARS], 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, EFFECTIVE TEMPERATURE, Astronomy and Astrophysics, Planets and satellites: detection, 500 Science, 620 Engineering, EVOLUTIONARY MODELS, Astrophysics - Solar and Stellar Astrophysics, FORMATION AND EVOLUTIONS, Space and Planetary Science, ATMOSPHERES [SATELLITES], SPECTRAL ENERGY DISTRIBUTION, Christian ministry, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], SATELLITES, STARS, Astrophysics - Earth and Planetary Astrophysics, PLANETS
Abstract

We report the discovery of a bright, brown dwarf companion to the star HIP 64892, imaged with VLT/SPHERE during the SHINE exoplanet survey. The host is a B9.5V member of the Lower-Centaurus-Crux subgroup of the Scorpius Centaurus OB association. The measured angular separation of the companion ($1.2705\pm0.0023$") corresponds to a projected distance of $159\pm12$ AU. We observed the target with the dual-band imaging and long-slit spectroscopy modes of the IRDIS imager to obtain its SED and astrometry. In addition, we reprocessed archival NACO L-band data, from which we also recover the companion. Its SED is consistent with a young (, Comment: 12 pages, 11 figures, accepted for publication in A&A

Published
2018
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49. Low wind effect on VLT/SPHERE: impact, mitigation strategy, and results

Author

Jean-François Sauvage, Arthur Vigan, Julien Milli, Konrad Tristam, Alexander Telle, Mamadou N'Diaye, Dimitri Mawet, David Mouillet, Zahed Wahhaj, Julien Girard, Cyril Pannetier, Claudia Reyes, Pierre Bourget, Thierry Fusco, Faustine Cantalloube, Jean-Luc Beuzit, Markus Kasper, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), 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), California Institute of Technology (CALTECH), 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), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), 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), 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), Close, Laird M., Schreiber, Laura, and Schmidt, Dirk

Subjects
Wavefront, Radiative cooling, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Image quality, business.industry, Phase (waves), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, 01 natural sciences, law.invention, 010309 optics, Telescope, Low emissivity, Cardinal point, Optics, 13. Climate action, law, 0103 physical sciences, Environmental science, Adaptive optics, business, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

The low wind effect is a phenomenon disturbing the phase of the wavefront in the pupil of a large telescope obstructed by spiders, in the absence of wind. It can be explained by the radiative cooling of the spiders, creating air temperature inhomogeneities across the pupil. Because it is unseen by traditional adaptive optics (AO) systems, thus uncorrected, it significantly degrades the quality of AO-corrected images. We provide a statistical analysis of the strength of this effect as seen by VLT/SPHERE after 4 years of operations. We analyse its dependence upon the wind and temperature conditions. We describe the mitigation strategy implemented in 2017: a specific coating with low thermal emissivity in the mid-infrared was applied on the spiders of Unit Telescope 3. We quantify the improvement in terms of image quality, contrast and wave front error using both focal plane images and measured phase maps., Comment: 20 pages, 21 figures, SPIE 2018 conference proceeding

Published
2018
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50. Statistical analysis and lessons learned of SPHERE adaptive optics performance

Author

Faustine Cantalloube, Jean-Luc Beuzit, Gael Chauvin, Carlos Correia, A. M. Lagrange, Cyril Pannetier, Kjetil Dohlen, D. Mouillet, N. Meunier, Arthur Vigan, T. Fusco, Markus Kasper, P. Delorme, D. Albert, A. Boccaletti, Julien Milli, J. F. Sauvage, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Unidad Mixta Internacional Franco-Chilena de Astromia, Universidad de Chile (CNRS/INSU), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), 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), and 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)

Subjects
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Computer science, 0103 physical sciences, Statistical analysis, Artificial intelligence, 010306 general physics, business, Adaptive optics, 010303 astronomy & astrophysics, 01 natural sciences
Abstract

International audience; The SPHERE instrument, dedicated to high contrast imaging on VLT, has been routinely operated for more than 3 years, over a large range of conditions and producing observations from visible to NIR. A central part of the instrument is the high order adaptive optics system, named SAXO, designed to deliver high Strehl image quality with a balanced performance budget for bright stars up to magnitude R=9. We take benefit now from the very large set of observations to revisit the assumptions and analysis made at the time of the design phase: we compare the actual AO behavior as a function of expectations. The data set consists of the science detector data, for both coronagraphic images and non-coronagraphic PSF calibrations, but also of AO internal data from the high frequency sensors and statistics computations from the real-time computer which are systematically archived, and finally of environmental data, monitored at VLT level. This work is supported and made possible by the SPHERE « Data Center » infrastructure hosted at Grenoble which provides an efficient access and the capability for the homogeneous analysis of this large and statistically-relevant data set. We review in a statistical manner the actual AO performance as a function of external conditions for different regimes and we discuss the possible performance metrics, either derived from AO internal data or directly from the high contrast images. We quantify the dependency of the actual performance on the most relevant environmental parameters. By comparison to earlier expectations, we conclude on the reliability of the usual AO modeling. We propose some practical criteria to optimize the queue scheduling and the expression of observer requirements ; finally, we revisit what could be the most important AO specifications for future high contrast imagers as a function of the primary science goals, the targets and the turbulence properties.

Published
2018
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