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13 results on '"W. Ogłoza"'

1. The Morphology of the Asteroidal Dust around White Dwarf Stars: Optical and Near-infrared Pulsations in G29-38

Author

Ted von Hippel, J. Farihi, J. L. Provencal, S. J. Kleinman, J. E. Pringle, A. Swan, G. Fontaine, J. J. Hermes, J. Sargent, Z. Savery, W. Cooper, V. Kim, V. Kozyreva, M. Krugov, A. Kusakin, A. Moss, W. Ogloza, Erika Pakštienė, A. Serebryanskiy, Eda Sonbas, B. Walter, M. Zejmo, and S. Zola

Subjects
Circumstellar dust, Asteroseismology, White dwarf stars, ZZ Ceti stars, Astrophysics, QB460-466
Abstract

More than 36 yr have passed since the discovery of the infrared excess from circumstellar dust orbiting the white dwarf G29-38, which at 17.5 pc it is the nearest and brightest of its class. The precise morphology of the orbiting dust remains only marginally constrained by existing data, subject to model-dependent inferences, and thus fundamental questions of its dynamical origin and evolution persist. This study presents a means to constrain the geometric distribution of the emitting dust using stellar pulsations measured at optical wavelengths as a variable illumination source of the dust, which reradiates primarily in the infrared. By combining optical photometry from the Whole Earth Telescope with 0.7–2.5 μ m spectroscopy obtained with SpeX at NASA’s Infrared Telescope Facility, we detect luminosity variations at all observed wavelengths, with variations at most wavelengths corresponding to the behavior of the pulsating stellar photosphere, but toward the longest wavelengths the light curves probe the corresponding time variability of the circumstellar dust. In addition to developing methodology, we find the pulsation amplitudes decrease with increasing wavelength for principal pulsation modes, yet increase beyond ≈2 μ m for nonlinear combination frequencies. We interpret these results as combination modes derived from the principal modes of identical ℓ values and discuss the implications for the morphology of the warm dust. We also draw attention to some discrepancies between our findings and theoretical expectations for the results of the nonlinearity imposed by the surface convection zone on mode–mode interactions and on the behavior of the first harmonic of the highest-amplitude pulsation mode.

Published
2024
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2. Radial Velocity Studies of Close Binary Stars.V

Author

Rucinski, S. M., Lu, W., Mochnacki, S. W., and Stachowski, W. Ogloza G.

Subjects
Astrophysics
Abstract

Radial-velocity measurements and sine-curve fits to the orbital velocity variations are presented for the fifth set of ten close binary systems: V376 And, EL Aqr, EF Boo, DN Cam, FN Cam, V776 Cas, SX Crv, V351 Peg, EQ Tau, KZ Vir. All systems are double-lined spectroscopic contact binaries (KZ Vir may be a low inclination, close, non-contact binary), with seven (all except EL Aqr, SX Crv and EQ Tau) being the recent photometric discoveries of the Hipparcos satellite project. The most interesting object is SX Crv, a contact system with an unprecedently low mass ratio, q=0.066+/-0.003, whose existence challenges the current theory of tidal stability of contact systems. Several of the studied systems are prime candidates for combined light and radial-velocity synthesis solutions., Comment: aastex5.0, 3 figures in PS; submitted to Astron.J

Published
2001
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3. Refinement of the convex shape model and tumbling spin state of (99942) Apophis using the 2020–2021 apparition data

Author

H.-J. Lee, M.-J. Kim, A. Marciniak, D.-H. Kim, H.-K. Moon, Y.-J. Choi, S. Zoła, J. Chatelain, T. A. Lister, E. Gomez, S. Greenstreet, A. Pál, R. Szakáts, N. Erasmus, R. Lees, P. Janse van Rensburg, W. Ogłoza, M. Dróżdż, M. Żejmo, K. Kamiński, M. K. Kamińska, R. Duffard, D.-G. Roh, H.-S. Yim, T. Kim, S. Mottola, F. Yoshida, D. E. Reichart, E. Sonbas, D. B. Caton, M. Kaplan, O. Erece, H. Yang, Ministerio de Ciencia e Innovación (España), and European Commission

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), asteroids: individual: (99942) Apophis – techniques: photometric, FOS: Physical sciences, Minor planets, Astronomy and Astrophysics, individual: (99942) Apophis [asteroids], Asteroids: individual: (99942) Apophis, photometric [techniques], Space and Planetary Science, Physics::Space Physics, minor planets, Astrophysics::Earth and Planetary Astrophysics, Techniques: photometric, Astrophysics - Earth and Planetary Astrophysics
Abstract

Context. The close approach of the near-Earth asteroid (99942) Apophis to Earth in 2029 will provide a unique opportunity to examine how the physical properties of the asteroid could be changed due to the Earth’s gravitational perturbation. As a result, the Republic of Korea is planning a rendezvous mission to Apophis. Aims. Our aim was to use photometric data from the apparitions in 2020−2021 to refine the shape model and spin state of Apophis. Methods. Using thirty-six 1- to 2-meter-class ground-based telescopes and the Transiting Exoplanet Survey Satellite, we carried out a photometric observation campaign throughout the 2020−2021 apparition. The convex shape model and spin state were refined using the light-curve inversion method. Results. According to our best-fit model, Apophis is rotating in a short-axis mode with rotation and precession periods of 264.178 h and 27.38547 h, respectively. The angular momentum vector orientation of Apophis was found to be (275°, −85°) in the ecliptic coordinate system. The ratio of the dynamic moments of inertia of this asteroid was fitted to Ia : Ib : Ic = 0.64 : 0.97 : 1, which corresponds to an elongated prolate ellipsoid. These findings regarding the spin state and shape model can be used to both design the space mission scenario and investigate the impact of the Earth’s tidal force during close encounters. © ESO 2022., This research has made use of the KMTNet system operated by the Korea Astronomy and Space Science Institute (KASI) and the data were obtained at three host sites of CTIO in Chile, SAAO in South Africa, and SSO in Australia. This Letter was partially based on observations obtained at the Bohyunsan Optical Astronomy Observatory (BOAO), the Sobaeksan Optical Astronomy Observatory (SOAO), and the Lemmonsan Optical Astronomy Observatory (LOAO), which is operated by the Korea Astronomy and Space Science Institute (KASI). This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; by products of the NEO search include images and catalogs from the survey area. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen’s University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile. A.P. and R.S. were supported by the K-138962 grant of the National Research, Development and Innovation Office. R.D. 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 Astrofísica de Andalucía (SEV-2017-0709). Based on observations collected at Centro Astronómico Hispano en Andalucía (CAHA) at Calar Alto, operated jointly by Instituto de Astrofísica de Andalucía (CSIC) and Junta de Andalucía. M.K. and O.E. thank TUBITAK National Observatory for a partial support in using T100 telescope with project number 20CT100-1743.

Published
2022

4. YETI follow-up observations of the T Tauri star CVSO 30 with transit-like dips

Author

Bischoff, R, primary, Raetz, St, additional, Fernández, M, additional, Mugrauer, M, additional, Neuhäuser, R, additional, Huang, P C, additional, Chen, W P, additional, Sota, A, additional, Ortega, J Jiménez, additional, Hambaryan, V V, additional, Zieliński, P, additional, Dróżdż, M, additional, Stenglein, W Ogłoza W, additional, Hohmann, E, additional, and Michel, K-U, additional

Published
2022
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5. Accretion disk in the binary system V367 Cygni

Author

W. Ogłoza and Staszek Zola

Subjects
Physics, Astronomy, Binary number, Astronomy and Astrophysics, Photometer, Astrophysics, Radius, Light curve, law.invention, Accretion disc, Space and Planetary Science, law, Observatory, Roche lobe, Binary system
Abstract

New photoelectric observations of the interacting binary V367 Cyg were made during two consecutive seasons, 1996 and 1997, using the two-channel photometer at Mt. Suhora Observatory. The BVRI light curves are analyzed and system parameters are derived for two alternative models: with and without an accretion disk. A contact conguration is obtained for the no-disk model. The semidetached model, with a disk around the invisible component gives a better t and, in addition, explains most of the observed features of V367 Cyg. The disk in V367 Cyg has a radius of about Rd =2 3R, almost completely lling the secondary component's Roche lobe. Mass is transferred from the less massive (3:3 M) to the more massive (4:0 M) star at a high rate of 5{7 10 5 M/yr.

Published
2001
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6. Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution

Author

J. Hanuš, J. Ďurech, M. Brož, A. Marciniak, B. D. Warner, F. Pilcher, R. Stephens, R. Behrend, B. Carry, D. Čapek, P. Antonini, M. Audejean, K. Augustesen, E. Barbotin, P. Baudouin, A. Bayol, L. Bernasconi, W. Borczyk, J.-G. Bosch, E. Brochard, L. Brunetto, S. Casulli, A. Cazenave, S. Charbonnel, B. Christophe, F. Colas, J. Coloma, M. Conjat, W. Cooney, H. Correira, V. Cotrez, A. Coupier, R. Crippa, M. Cristofanelli, Ch. Dalmas, C. Danavaro, C. Demeautis, T. Droege, R. Durkee, N. Esseiva, M. Esteban, M. Fagas, G. Farroni, M. Fauvaud, S. Fauvaud, F. Del Freo, L. Garcia, S. Geier, C. Godon, K. Grangeon, H. Hamanowa, N. Heck, S. Hellmich, D. Higgins, R. Hirsch, M. Husarik, T. Itkonen, O. Jade, K. Kamiński, P. Kankiewicz, A. Klotz, R. A. Koff, A. Kryszczyńska, T. Kwiatkowski, A. Laffont, A. Leroy, J. Lecacheux, Y. Leonie, C. Leyrat, F. Manzini, A. Martin, G. Masi, D. Matter, J. Michałowski, M. J. Michałowski, T. Michałowski, J. Michelet, R. Michelsen, E. Morelle, S. Mottola, R. Naves, J. Nomen, J. Oey, W. Ogłoza, A. Oksanen, D. Oszkiewicz, P. Pääkkönen, M. Paiella, H. Pallares, J. Paulo, M. Pavic, B. Payet, M. Polińska, D. Polishook, R. Poncy, Y. Revaz, C. Rinner, M. Rocca, A. Roche, D. Romeuf, R. Roy, H. Saguin, P. A. Salom, S. Sanchez, G. Santacana, T. Santana-Ros, J.-P. Sareyan, K. Sobkowiak, S. Sposetti, D. Starkey, R. Stoss, J. Strajnic, J.-P. Teng, B. Trégon, A. Vagnozzi, F. P. Velichko, N. Waelchli, K. Wagrez, H. Wücher, Astronomical Institute of Charles University, Charles University [Prague] (CU), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Palmer Divide Observatory, Organ Mesa Observatory, Goat Mountain Astronomical Research Station, Geneva Observatory, Université de Genève = University of Geneva (UNIGE), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Astronomical Institute of the Czech Academy of Sciences (ASU / CAS), Czech Academy of Sciences [Prague] (CAS), Observatoire de Bédoin, Observatoire de Chinon, Courbes de rotation d'astéroïdes, de comètes et d'étoiles variables (CdR & CdL group), CdR & CdL group, Association T60, Observatoire Midi-Pyrénées, Observatoire Midi-Pyrénées (OMP), 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, Harfleur Observatory, Observatoire des Engarouines, Collonges Observatory, Chercheur indépendant, Observatoire N°139 d'Antibes, Osservatorio Colleverde di Guidonia, Observatoire de Saint-Sulpice N°947, DPHY, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), 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), Observatorio de San Gervasi, Observatoire de Cabris, Blackberry Observatory, Centre d'Astronomie de Saint-Michel l'Observatoire, Observatoire de Sainte-Hélène, Observatorio Astronómico de Tradate, 138 Village-Neuf, The Amateur Sky Survey (TASS), The Amateur Sky Survey, Shed of Science Observatory, Association AstroQueyras, Association des Utilisateurs de Détecteurs Electroniques (AUDE), Association des Utilisateurs de Détecteurs Electroniques, Observatoire du Bois de Bardon, Dark Cosmology Centre (DARK), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Nordic Optical Telescope (NOT), Instituto de Astrofisica de Canarias (IAC), Hamanowa Astronomical Observatory, DLR Institute of Planetary Research, German Aerospace Center (DLR), Hunters Hill Observatory, Skalnaté Pleso Observatory, A83 Jakokoski Observatory, Institute of Physics [Kielce], Jan Kochanowski University, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), 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)-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 -Centre National de la Recherche Scientifique (CNRS), Antelope Hills Observatory, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), 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), Stazione Astronomica di Sozzago, Forte Software, Scottish Universities Physics Alliance, Institute for Astronomy (SUPA), University of Edinburgh, Club d'Astronomie Lyon Ampéré [Vaulx-en-Velin] (CALA), Nyrölä Observatory (NYTT), Observatorio Montcabre, Observatorio Astronómico de Mallorca (OAM), Observatorio Astronómico de Mallorca, Kingsgrove Observatory, Mt. Suhora Observatory, Pedagogical University, Astronomy Department, Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), François-Xavier Bagnoud Observatory, Blauvac Obsevatory, Blauvac Observatory, Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Gnosca Observatory, DeKalb Observatory, Observatoire astronomique des Makes, Laboratoire Kastler Brossel (LKB (Lhomond)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Institute of Astronomy [Kharkiv], V.N. Karazin Kharkiv National University (KhNU), University of Geneva [Switzerland], European Space Agency (ESA), 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), 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), University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse 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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), University of Helsinki-University of Helsinki, Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, photometry, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], media_common.quotation_subject, Population, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Inverse transform sampling, Astrophysics, 01 natural sciences, Photometry (optics), models, Observatory, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, Scaling, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, media_common, Earth and Planetary Astrophysics (astro-ph.EP), Physics, education.field_of_study, Physical model, Minor planets, Astronomy and Astrophysics, Asteroids: general, 13. Climate action, Space and Planetary Science, Sky, Asteroid, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

The larger number of models of asteroid shapes and their rotational states derived by the lightcurve inversion give us better insight into both the nature of individual objects and the whole asteroid population. With a larger statistical sample we can study the physical properties of asteroid populations, such as main-belt asteroids or individual asteroid families, in more detail. Shape models can also be used in combination with other types of observational data (IR, adaptive optics images, stellar occultations), e.g., to determine sizes and thermal properties. We use all available photometric data of asteroids to derive their physical models by the lightcurve inversion method and compare the observed pole latitude distributions of all asteroids with known convex shape models with the simulated pole latitude distributions. We used classical dense photometric lightcurves from several sources and sparse-in-time photometry from the U.S. Naval Observatory in Flagstaff, Catalina Sky Survey, and La Palma surveys (IAU codes 689, 703, 950) in the lightcurve inversion method to determine asteroid convex models and their rotational states. We also extended a simple dynamical model for the spin evolution of asteroids used in our previous paper. We present 119 new asteroid models derived from combined dense and sparse-in-time photometry. We discuss the reliability of asteroid shape models derived only from Catalina Sky Survey data (IAU code 703) and present 20 such models. By using different values for a scaling parameter cYORP (corresponds to the magnitude of the YORP momentum) in the dynamical model for the spin evolution and by comparing synthetics and observed pole-latitude distributions, we were able to constrain the typical values of the cYORP parameter as between 0.05 and 0.6., Accepted for publication in A&A, January 15, 2013

Published
2013
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7. New and updated convex shape models of asteroids based on optical data from a large collaboration network

Author

J. Hanuš, J. Ďurech, D. A. Oszkiewicz, R. Behrend, B. Carry, M. Delbo, O. Adam, V. Afonina, R. Anquetin, P. Antonini, L. Arnold, M. Audejean, P. Aurard, M. Bachschmidt, B. Baduel, E. Barbotin, P. Barroy, P. Baudouin, L. Berard, N. Berger, L. Bernasconi, J-G. Bosch, S. Bouley, I. Bozhinova, J. Brinsfield, L. Brunetto, G. Canaud, J. Caron, F. Carrier, G. Casalnuovo, S. Casulli, M. Cerda, L. Chalamet, S. Charbonnel, B. Chinaglia, A. Cikota, F. Colas, J.-F. Coliac, A. Collet, J. Coloma, M. Conjat, E. Conseil, R. Costa, R. Crippa, M. Cristofanelli, Y. Damerdji, A. Debackère, A. Decock, Q. Déhais, T. Déléage, S. Delmelle, C. Demeautis, M. Dróżdż, G. Dubos, T. Dulcamara, M. Dumont, R. Durkee, R. Dymock, A. Escalante del Valle, N. Esseiva, R. Esseiva, M. Esteban, T. Fauchez, M. Fauerbach, M. Fauvaud, S. Fauvaud, E. Forné, C. Fournel, D. Fradet, J. Garlitz, O. Gerteis, C. Gillier, M. Gillon, R. Giraud, J.-P. Godard, R. Goncalves, Hiroko Hamanowa, Hiromi Hamanowa, K. Hay, S. Hellmich, S. Heterier, D. Higgins, R. Hirsch, G. Hodosan, M. Hren, A. Hygate, N. Innocent, H. Jacquinot, S. Jawahar, E. Jehin, L. Jerosimic, A. Klotz, W. Koff, P. Korlevic, E. Kosturkiewicz, P. Krafft, Y. Krugly, F. Kugel, O. Labrevoir, J. Lecacheux, M. Lehký, A. Leroy, B. Lesquerbault, M. J. Lopez-Gonzales, M. Lutz, B. Mallecot, J. Manfroid, F. Manzini, A. Marciniak, A. Martin, B. Modave, R. Montaigut, J. Montier, E. Morelle, B. Morton, S. Mottola, R. Naves, J. Nomen, J. Oey, W. Ogłoza, M. Paiella, H. Pallares, A. Peyrot, F. Pilcher, J.-F. Pirenne, P. Piron, M. Polińska, M. Polotto, R. Poncy, J. P. Previt, F. Reignier, D. Renauld, D. Ricci, F. Richard, C. Rinner, V. Risoldi, D. Robilliard, D. Romeuf, G. Rousseau, R. Roy, J. Ruthroff, P. A. Salom, L. Salvador, S. Sanchez, T. Santana-Ros, A. Scholz, G. Séné, B. Skiff, K. Sobkowiak, P. Sogorb, F. Soldán, A. Spiridakis, E. Splanska, S. Sposetti, D. Starkey, R. Stephens, A. Stiepen, R. Stoss, J. Strajnic, J.-P. Teng, G. Tumolo, A. Vagnozzi, B. Vanoutryve, J. M. Vugnon, B. D. Warner, M. Waucomont, O. Wertz, M. Winiarski, M. Wolf, Charles University [Prague] (CU), Astronomical Institute of Charles University, Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Geneva Observatory, Université de Genève = University of Geneva (UNIGE), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), 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), Observatoire de Bédoin, Observatoire de Chinon, Association des Utilisateurs de Détecteurs Electroniques, Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), Harfleur Observatory, Ressources des terroirs - UMR 8575, Centre National de la Recherche Scientifique (CNRS), Les Engarouines Observatory, Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Chercheur indépendant, Laboratoire d'optique des solides (LOS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Centre de Recherche Saint-Antoine (UMRS893), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Association T60, Observatoire Midi-Pyrénées, Observatoire Midi-Pyrénées (OMP), 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, Courbes de rotation d'astéroïdes, de comètes et d'étoiles variables (CdR & CdL group), CdR & CdL group, Physik-Institut, Universität Zürich [Zürich] = University of Zurich (UZH), Gestion environnementale et traitement biologique des déchets (UR GERE), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Observatorio de San Gervasi, Observatoire de Cabris, Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatorio Astronómico de Tradate, Observatoire N°139 d'Antibes, 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), 138 Village-Neuf, Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Shed of Science Observatory, Association AstroQueyras, Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Observatoire du Bois de Bardon, Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Ciências Exatas e Tecnológicas [Viçosa], Universidade Federal de Viçosa = Federal University of Viçosa (UFV), Hamanowa Astronomical Observatory, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), European Southern Observatory (ESO), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), 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)-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 -Centre National de la Recherche Scientifique (CNRS), Observatoire Chante-Perdrix, 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), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Stazione Astronomica di Sozzago, Milieux aquatiques, écologie et pollutions (UR MALY), German Aerospace Center (DLR), Observatorio Montcabre, Observatorio Astronómico de Mallorca (OAM), Observatorio Astronómico de Mallorca, Kingsgrove Observatory, Gestion Territoriale de l'Eau et de l'environnement (UMR GESTE), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Organ Mesa Observatory, Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Association des Utilisateurs de Détecteurs Electroniques (AUDE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Laboratoire de Recherche sur la Réactivité des Solides (LRRS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Gnosca Observatory, DeKalb Observatory, Laboratoire de Physique Atmosphérique et Planétaire (LPAP), Observatoire astronomique des Makes, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Argelander Institute for Astronomy (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Institute of Neuropathology, University hospital of Zurich [Zurich], Charles University [Prague], University of Helsinki-University of Helsinki, University of Geneva [Switzerland], European Space Agency (ESA), 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), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de la Matière Condensée (EA 2081), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Université de Genève (UNIGE), Centre de Recherche Saint-Antoine (CR Saint-Antoine), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Universität Zürich [Zürich] (UZH), L2EP - Équipe Réseaux, 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, Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Observatoire Midi-Pyrénées and Association T60, Laboratoire de photonique et de nanostructures (LPN), Universidade Federal de Vicosa (UFV), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), 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), Centre d'études de chimie métallurgique (CECM), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), University of St Andrews. School of Physics and Astronomy, 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, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), 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), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), 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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), National Science Centre (Poland), Czech Science Foundation, Centre National D'Etudes Spatiales (France), Charles University [Prague] [CU], European Space Astronomy Centre [ESAC], Joseph Louis LAGRANGE [LAGRANGE], Institut de Recherches Subatomiques [IReS], Laboratoire d'Annecy de Physique des Particules [LAPP], Géosciences Paris Sud [GEOPS], Laboratoire d'optique des solides [LOS], Observatoire Astronomique de l'Université de Genève [ObsGE], Gestion environnementale et traitement biologique des déchets [UR GERE], Observatoire astronomique de Strasbourg [ObAS], Science et Ingénierie des Matériaux et Procédés [SIMaP], Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA], Interactions et dynamique des environnements de surface [IDES], Laboratoire de photonique et de nanostructures [LPN], European Southern Observatory [ESO], Institut de recherche en astrophysique et planétologie [IRAP], Laboratoire d'études spatiales et d'instrumentation en astrophysique [LESIA], Milieux aquatiques, écologie et pollutions [UR MALY], German Aerospace Center [DLR], Laboratoire de l'Accélérateur Linéaire [LAL], Université Claude Bernard Lyon 1 [UCBL], Laboratoire de Recherche sur la Réactivité des Solides [LRRS], Laboratoire de l'intégration, du matériau au système [IMS], Laboratoire de Physique Atmosphérique et Planétaire [LPAP], INAF - Osservatorio Astronomico di Padova [OAPD], Argelander Institute for Astronomy [AlfA], ITA, USA, GBR, FRA, DEU, and ESP

Subjects
Solar System, 010504 meteorology & atmospheric sciences, Computer science, media_common.quotation_subject, FOS: Physical sciences, Inverse transform sampling, 01 natural sciences, Gravitation, Photometry (optics), Methods: observational, 0103 physical sciences, QB Astronomy, observational [Methods], Shape optimization, asteroids: general / techniques: photometric / methods: observational / methods: numerical, 010303 astronomy & astrophysics, Scaling, QC, ComputingMilieux_MISCELLANEOUS, QB, 0105 earth and related environmental sciences, media_common, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], numerical [Methods], Methods: numerical, photometric [Techniques], Minor planets, Astronomy, Astronomy and Astrophysics, 3rd-DAS, QC Physics, Minor planets, asteroids: general, Space and Planetary Science, Sky, Asteroid, Physics::Space Physics, minor planets, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [Asteroids], Techniques: photometric, Astrophysics - Earth and Planetary Astrophysics, general [minor planets, asteroids]
Abstract

Context. Asteroid modeling efforts in the last decade resulted in a comprehensive dataset of almost 400 convex shape models and their rotation states. These efforts already provided deep insight into physical properties of main-belt asteroids or large collisional families. Going into finer detail (e.g., smaller collisional families, asteroids with sizes 20 km) requires knowledge of physical parameters of more objects. Aims. We aim to increase the number of asteroid shape models and rotation states. Such results provide important input for further studies, such as analysis of asteroid physical properties in different populations, including smaller collisional families, thermophysical modeling, and scaling shape models by disk-resolved images, or stellar occultation data. This provides bulk density estimates in combination with known masses, but also constrains theoretical collisional and evolutional models of the solar system. Methods. We use all available disk-integrated optical data (i.e., classical dense-in-time photometry obtained from public databases and through a large collaboration network as well as sparse-in-time individual measurements from a few sky surveys) as input for the convex inversion method, and derive 3D shape models of asteroids together with their rotation periods and orientations of rotation axes. The key ingredient is the support of more that 100 observers who submit their optical data to publicly available databases. Results. We present updated shape models for 36 asteroids, for which mass estimates are currently available in the literature, or for which masses will most likely be determined from their gravitational influence on smaller bodies whose orbital deflections will be observed by the ESA Gaia astrometric mission. Moreover, we also present new shape model determinations for 250 asteroids, including 13 Hungarias and three near-Earth asteroids. The shape model revisions and determinations were enabled by using additional optical data from recent apparitions for shape optimization. © 2016 ESO., J.H. greatly appreciates the CNES post-doctoral fellowship program. J.H. and M.D. were supported by the project under the contract 11-BS56-008 (SHOCKS) of the French Agence National de la Recherche (ANR), JD by grant GACR 15-04816S of the Czech Science Foundation, DO by the grant NCN 2012/S/ST9/00022 of Polish National Science Center, and A. Marciniak by grant 2014/13/D/ST9/01818 of Polish National Science Center.

Published
2016
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8. Observations of the pulsating subdwarf B star Feige 48: Constraints on evolution and companions

Author

M. D. Reed, S. D. Kawaler, S. Zola, X. J. Jiang, S. Dreizler, S. L. Schuh, J. L. Deetjen, R. Kalytis, E. Meištas, R. Janulis, D. Ališauskas, J. Krzesiński, M. Vuckovic, P. Moskalik, W. Ogłoza, A. Baran, G. Stachowski, D. W. Kurtz, J. M. González Pérez, A. Mukadam, T. K. Watson, C. Koen, P. A. Bradley, M. S. Cunha, M. Kilic, E. W. Klumpe, R. F. Carlton, G. Handler, D. Kilkenny, R. Riddle, N. Dolez, G. Vauclair, M. Chevreton, M. A. Wood, A. Grauer, G. Bromage, J. E. Solheim, R. Østensen, A. Ulla, M. Burleigh, S. Good, Ö. Hürkal, R. Anderson, E. Pakstiene, Department of Physics, Astronomy, and Materials Science, Missouri State University, Department of Physics and Astronomy, Iowa State University, Astronomical Observatory, Jagiellonia University, National Astronomical Observatoires-CAS, Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, Institute of Material Science and Applied Research of Vilnius University, Astronomical Observatory, Institute of Theoretical Physics and Astronomy, Astronomical Observatory, Mount Suhora Observatory, Cracow Pedagogical University, Centrum Astronomiczne im. M. Kopernika, Warszawa (CAMK), Centre for Astrophysics, University of Central Lancashire, Institutt for Fysikk, Universitetet i Tromsø, Department of Astronomy, University of Texas, Southwestern University, Los Alamos National Laboratory (LANL), Centro de Astrofisica da Universidade do Porto (CAUP), Department of Physics and Astronomy, Middle Tennessee State University, South African Astronomical Observatory (SAAO), Observatoire Midi-Pyrénées (OMP), 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, Departement d'Astrophysique Extragalactique et de Cosmologie (DAEC), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), 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), Pôle Astronomie du LESIA, 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Department of Physics and Space Sciences and SARA Observatory, Florida Institute of Technology, Melbourne, Department of Physics and Astronomy, University of Arkansas, Isaac Newton Group of Telescopes, Universidade de Vigo, Department of Physics and Astronomy, University of Leicester, Department of Astronomy and Space Sciences, Ege University, Department of Physics and Astronomy, University of North Carolina, and Ege Üniversitesi

Subjects
oscillations [stars], Subdwarf B star, stars : individual (Feige 48), FOS: Physical sciences, Astrophysics, Star (graph theory), 01 natural sciences, Stability (probability), stars : oscillations, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, individual (Feige 48) [stars], Physics, 010308 nuclear & particles physics, variables: other [stars], Astrophysics (astro-ph), Mode (statistics), Astronomy and Astrophysics, Horizontal branch, Subdwarf, stars : variables : other, Stars, Amplitude, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Since pulsating subdwarf B (sdBV or EC14026) stars were first discovered (Kilkenny et al, 1997), observational efforts have tried to realize their potential for constraining the interior physics of extreme horizontal branch (EHB) stars. Difficulties encountered along the way include uncertain mode identifications and a lack of stable pulsation mode properties. Here we report on Feige 48, an sdBV star for which follow-up observations have been obtained spanning more than four years, which shows some stable pulsation modes. We resolve the temporal spectrum into five stable pulsation periods in the range 340 to 380 seconds with amplitudes less than 1%, and two additional periods that appear in one dataset each. The three largest amplitude periodicities are nearly equally spaced, and we explore the consequences of identifying them as a rotationally split l=1 triplet by consulting with a representative stellar model. The general stability of the pulsation amplitudes and phases allows us to use the pulsation phases to constrain the timescale of evolution for this sdBV star. Additionally, we are able to place interesting limits on any stellar or planetary companion to Feige 48., accepted for publication in MNRAS

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9. Unusual Accretion Disk in Algol - Type Binaries - KU Cyg

Author

T. Szymanski, S. Zola, M. Siwak, and W. Ogloza

Subjects
Astronomy, QB1-991
Abstract

We present new results obtained from analysis of Hα double peaked emission line observed at several phases. We confirm the results that KU Cyg harbours an eccentric shape, precessing accretion disk. The system mass ratio q=0.13 may indicat

Published
2010
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10. Signatures of the Disk–Jet Coupling in the Broad-line Radio Quasar 4C+74.26.

Author

G. Bhatta, Ł. Stawarz, A. Markowitz, K. Balasubramaniam, S. Zola, A. A. Zdziarski, M. Jamrozy, M. Ostrowski, A. Kuzmicz, W. Ogłoza, M. Dróżdż, M. Siwak, D. Kozieł-Wierzbowska, B. Debski, T. Kundera, G. Stachowski, J. Machalski, V. S. Paliya, and D. B. Caton

Subjects
QUASARS, LUMINOSITY, JETS (Nuclear physics), DISKS (Astrophysics), KINETIC energy
Abstract

We explore the disk–jet connection in the broad-line radio quasar 4C+74.26, utilizing the results of multiwavelength monitoring of the source. The target is unique in that its radiative output at radio wavelengths is dominated by a moderately beamed nuclear jet, at optical frequencies by the accretion disk, and in the hard X-ray range by the disk corona. Our analysis reveals a correlation (local and global significance of 96% and 98% respectively) between the optical and radio bands, with the disk lagging behind the jet by 250 ± 42 days. We discuss the possible explanation for this, speculating that the observed disk and the jet flux changes are generated by magnetic fluctuations originating within the innermost parts of a truncated disk, and that the lag is related to a delayed radiative response of the disk when compared with the propagation timescale of magnetic perturbations along a relativistic outflow. This scenario is supported by re-analysis of NuSTAR data, modeled in terms of a relativistic reflection from the disk illuminated by the coronal emission, which returns an inner disk radius . We discuss the global energetics in the system, arguing that while the accretion proceeds at the Eddington rate, with the accretion-related bolometric luminosity Lbol ∼ 9 × 1046 erg s−1 ∼ 0.2LEdd, the jet total kinetic energy Lj ∼ 4 × 1044 erg s−1, inferred from the dynamical modeling of the giant radio lobes in the source, constitutes only a small fraction of the available accretion power. [ABSTRACT FROM AUTHOR]

Published
2018
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12. A Search for QPOs in the Blazar OJ287: Preliminary Results from the 2015/2016 Observing Campaign

Author

S. Zola, M. Valtonen, G. Bhatta, A. Goyal, B. Debski, A. Baran, J. Krzesinski, M. Siwak, S. Ciprini, A. Gopakumar, H. Jermak, K. Nilsson, D. Reichart, K. Matsumoto, K. Sadakane, K. Gazeas, M. Kidger, V. Piirola, F. Alicavus, K. S. Baliyan, A. Berdyugin, D. Boyd, M. Campas Torrent, F. Campos, J. Carrillo Gómez, D. B. Caton, V. Chavushyan, J. Dalessio, D. Dimitrov, M. Drozdz, H. Er, A. Erdem, A. Escartin Pérez, V. Fallah Ramazani, A. V. Filippenko, F. Garcia, F. Gómez Pinilla, M. Gopinathan, J. B. Haislip, J. Harmanen, R. Hudec, G. Hurst, K. M. Ivarsen, M. Jelinek, A. Joshi, M. Kagitani, N. Kaur, W. C. Keel, A. P. LaCluyze, B. C. Lee, E. Lindfors, J. Lozano de Haro, J. P. Moore, M. Mugrauer, R. Naves Nogues, A. W. Neely, R. H. Nelson, W. Ogloza, S. Okano, J. C. Pandey, M. Perri, P. Pihajoki, G. Poyner, J. Provencal, T. Pursimo, A. Raj, R. Reinthal, S. Sadegi, T. Sakanoi, Sameer, J.-L. Salto González, T. Schweyer, F. C. Soldán Alfaro, N. Karaman, E. Sonbas, I. Steele, J. T. Stocke, J. Strobl, L. O. Takalo, T. Tomov, L. Tremosa Espasa, J. R. Valdes, J. Valero Pérez, F. Verrecchia, J. R. Webb, M. Yoneda, M. Zejmo, W. Zheng, J. Telting, J. Saario, T. Reynolds, A. Kvammen, E. Gafton, R. Karjalainen, and P. Blay

Subjects
galaxies: active, BL Lacertae objects: individual (OJ287), supermassive black holes, Astronomy, QB1-991
Abstract

We analyse the light curve in the R band of the blazar OJ287, gathered during the 2015/2016 observing season. We did a search for quasi-periodic oscillations (QPOs) using several methods over a wide range of timescales. No statistically significant periods were found in the high-frequency domain both in the ground-based data and in Kepler observations. In the longer-period domain, the Lomb–Scargle periodogram revealed several peaks above the 99% significance level. The longest one—about 95 days—corresponds to the innermost stable circular orbit (ISCO) period of the more massive black hole. The 43-day period could be an alias, or it can be attributed to accretion in the form of a two-armed spiral wave.

Published
2016
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13. DETECTION OF POSSIBLE QUASI-PERIODIC OSCILLATIONS IN THE LONG-TERM OPTICAL LIGHT CURVE OF THE BL LAC OBJECT OJ 287.

Author

G. Bhatta, Ł. Stawarz, M. Ostrowski, D. Kozieł-Wierzbowska, B. Debski, T. Kundera, S. Zola, M. Winiarski, W. Ogłoza, M. Dróżdż, M. Siwak, G. Stachowski, A. Liakos, K. Gazeas, and V. S. Paliya

Subjects
BL Lacertae objects, BLACK holes, ACCRETION disks, OSCILLATIONS, ELECTRICAL harmonics, DATA acquisition systems
Abstract

The detection of periodicity in the broadband non-thermal emission of blazars has so far been proven to be elusive. However, there are a number of scenarios that could lead to quasi-periodic variations in blazar light curves. For example, an orbital or thermal/viscous period of accreting matter around central supermassive black holes could, in principle, be imprinted in the multi-wavelength emission of small-scale blazar jets, carrying such crucial information about plasma conditions within the jet launching regions. In this paper, we present the results of our time series analysis of the ∼9.2 yr long, and exceptionally well-sampled, optical light curve of the BL Lac object OJ 287. The study primarily used the data from our own observations performed at the Mt. Suhora and Kraków Observatories in Poland, and at the Athens Observatory in Greece. Additionally, SMARTS observations were used to fill some of the gaps in the data. The Lomb–Scargle periodogram and the weighted wavelet Z-transform methods were employed to search for possible quasi-periodic oscillations in the resulting optical light curve of the source. Both methods consistently yielded a possible quasi-periodic signal around the periods of ∼400 and ∼800 days, the former with a significance (over the underlying colored noise) of . A number of likely explanations for this are discussed, with preference given to a modulation of the jet production efficiency by highly magnetized accretion disks. This supports previous findings and the interpretation reported recently in the literature for OJ 287 and other blazar sources. [ABSTRACT FROM AUTHOR]

Published
2016
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