Year: 2017
Type: article
Abstract: Aims. The SHINE program is a high-contrast near-infrared survey of 600 young, nearby stars aimed at searching for and characterizing new planetary systems using VLT/SPHERE’s unprecedented high-contrast and high-angular-resolution imaging capabilities. It is also intended to place statistical constraints on the rate, mass and orbital distributions of the giant planet population at large orbits as a function of the stellar host mass and age to test planet-formation theories. Methods. We used the IRDIS dual-band imager and the IFS integral field spectrograph of SPHERE to acquire high-contrast coronagraphic differential near-infrared images and spectra of the young A2 star HIP 65426. It is a member of the ~17 Myr old Lower Centaurus-Crux association. Results. At a separation of 830 mas (92 au projected) from the star, we detect a faint red companion. Multi-epoch observations confirm that it shares common proper motion with HIP 65426. Spectro-photometric measurements extracted with IFS and IRDIS between 0.95 and 2.2 μ m indicate a warm, dusty atmosphere characteristic of young low-surface-gravity L5-L7 dwarfs. Hot-start evolutionary models predict a luminosity consistent with a 6–12 M Jup , T eff = 1300–1600 K and R = 1.5 ± 0.1 R Jup giant planet. Finally, the comparison with Exo-REM and PHOENIX BT-Settl synthetic atmosphere models gives consistent effective temperatures but with slightly higher surface gravity solutions of log ( g ) = 4.0–5.0 with smaller radii (1.0–1.3 R Jup ). Conclusions. Given its physical and spectral properties, HIP 65426 b occupies a rather unique placement in terms of age, mass, and spectral-type among the currently known imaged planets. It represents a particularly interesting case to study the presence of clouds as a function of particle size, composition, and location in the atmosphere, to search for signatures of non-equilibrium chemistry, and finally to test the theory of planet formation and evolution.
Source: Astronomy and Astrophysics
Authors: G. Chauvin, S. Desidera, A.-M. Lagrange, A. Vigan, R. Gratton, M. Langlois, M. Bonnefoy, J.-L. Beuzit, M. Feldt, D. Mouillet, M. Meyer, A. Cheetham, B. Biller, A. Boccaletti, V. D’Orazi, R. Galicher, J. Hagelberg, A.-L. Maire, D. Mesa, J. Olofsson, M. Samland, T. O. B. Schmidt, E. Sissa, M. Bonavita, B. Charnay, M. Cudel, S. Daemgen, P. Delorme, P. Janin-Potiron, M. Janson, M. Keppler, H. Le Coroller, R. Ligi, G. D. Marleau, S. Messina, P. Mollière, C. Mordasini, A. Müller, S. Peretti, C. Perrot, L. Rodet, D. Rouan, A. Zurlo, C. Dominik, T. Henning, F. Menard, H.-M. Schmid, M. Turatto, S. Udry, F. Vakili, L. Abe, J. Antichi, A. Baruffolo, P. Baudoz, J. Baudrand, P. Blanchard, A. Bazzon, T. Buey, M. Carbillet, M. Carle, J. Charton, E. Cascone, R. Claudi, A. Costille, A. Deboulbe, V. De Caprio, K. Dohlen, D. Fantinel, P. Feautrier, T. Fusco, P. Gigan, E. Giro, D. Gisler, L. Gluck, N. Hubin, E. Hugot, M. Jaquet, M. Kasper, F. Madec, Y. Magnard, P. Martinez, D. Maurel, D. Le Mignant, O. Möller-Nilsson, M. Llored, T. Moulin, A. Origné, A. Pavlov, D. Perret, C. Petit, J. Pragt, P. Puget, P. Rabou, J. Ramos, R. Rigal, S. Rochat, R. Roelfsema, G. Rousset, A. Roux, B. Salasnich, J.-F. Sauvage, A. Sevin, C. Soenke, E. Stadler, M. Suarez, L. Weber, F. Wildi, S. Antoniucci, J.-C. Augereau, J.-L. Baudino, W. Brandner, N. Engler, J. Girard, C. Gry, Q. Kral, T. Kopytova, E. Lagadec, J. Milli, C. Moutou, J. Schlieder, J. Szulágyi, C. Thalmann, Z. Wahhaj
Institutions: Centre National de la Recherche Scientifique, Institut de Planétologie et d'Astrophysique de Grenoble, University of Chile, Université Grenoble Alpes, Osservatorio Astronomico di Padova, National Institute for Astrophysics, Aix-Marseille Université, Laboratoire d’Astrophysique de Marseille, École Normale Supérieure de Lyon, Centre de Recherche Astrophysique de Lyon, Max Planck Institute for Astronomy, University of Michigan, ETH Zurich, University of Geneva, Royal Observatory, University of Edinburgh, Université Paris Sciences et Lettres, Observatoire de Paris, Sorbonne Paris Cité, Laboratoire d’études spatiales et d’instrumentation en astrophysique, University of Valparaíso, Université Côte d'Azur, Observatoire de la Côte d’Azur, Stockholm University, AlbaNova, University of Bern, Osservatorio Astrofisico di Catania, Universidad Diego Portales, University of Amsterdam, Arcetri Astrophysical Observatory, Astronomical Observatory of Capodimonte, Office National d'Études et de Recherches Aérospatiales, European Southern Observatory, Astronomical Observatory of Rome, University of Oxford, European Southern Observatory, University of Cambridge, Ural Federal University, Arizona State University, Canada–France–Hawaii Telescope, Goddard Space Flight Center
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, European Space Agency, European Commission, Agence Nationale de la Recherche, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Eidgenössische Technische Hochschule Zürich, Centre National de la Recherche Scientifique, Ministerio de Ciencia e Innovación, Max-Planck-Institut für Astronomie, Centro de Estudos Ambientais e Marinhos, Universidade de Aveiro, Science and Technology Facilities Council, Office National d'études et de Recherches Aérospatiales, U.S. Naval Observatory
Awards: Optical Infrared Co-ordination Network for Astronomy, G38854245, G3925786472, G39620777, G4030817349, G4333900429, G4369834866, G4832770986, GIant Planetary Systems Exploration, G5040547664, G6216976133, G623270878, Optical Infrared Coordination Network for Astronomy, G8085321155, Innovative strategies for observing and modelling natural systems, G849075540, G87242835, Nutrition-functional tailored food from microalgal-dairy hybrid systems through in-line sensing and predictive control of multiphase structure extrusion processing
OpenAlex ID: W2727520976