Academic Journal
A dusty benchmark brown dwarf near the ice line of HD 72946
| العنوان: | A dusty benchmark brown dwarf near the ice line of HD 72946 |
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| المؤلفون: | Alcalá, J. M., Majidi, F. Z., Frasca, A., Manara, C. F., Rigliaco, E., Gratton, R., Covino, E., Claudi, R., d'Orazi, V., Lazzoni, C., Mesa, D., Schlieder, J. E., Vigan, A., D’orazi, V., Maire, A. -L., Baudino, J. -L., Desidera, S., Messina, S., Brandner, W., Godoy, N., Cantalloube, F., Galicher, R., Bonnefoy, M., Hagelberg, J., Olofsson, J., Absil, O., Chauvin, G., Henning, T., Langlois, M |
| المساهمون: | INAF - Osservatorio Astrofisico di Catania (OACT), Istituto Nazionale di Astrofisica (INAF), INAF - Osservatorio Astronomico di Padova (OAPD), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Max Planck Institute for Astronomy (MPIA), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), ANR-14-CE33-0018,GIPSE,Exploration des planetes géantes extrasolaires(2014) |
| المصدر: | ISSN: 0004-6361. |
| بيانات النشر: | CCSD EDP Sciences |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | brown dwarfs, methods: data analysis, stars: individual: HD 72946, planets and satellites: dynamical evolution and stability, techniques: high angular resolution, techniques: image processing, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics, [PHYS]Physics [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], [SDU]Sciences of the Universe [physics] |
| الوصف: | Accepted for publication in A&A, 10 pages, 10 figures, 1 table. Includes language editing. Missing references in Sect. 6 and Appendix E added ; International audience ; Context. HD72946 is a bright and nearby solar-type star hosting a low-mass companion at long period (P~16 yr) detected with the radial velocities (RV) method. The companion has a minimum mass of 60.4+/-2.2 MJ and might be a brown dwarf. Its expected semi-major axis of ~243 mas makes it a suitable target for further characterization with high-contrast imaging, in particular to measure its inclination, mass, and spectrum and thus definitely establish its substellar nature. Aims. We aim to further characterize the orbit, atmosphere, and physical nature of HD72946B. Methods. We present high-contrast imaging data in the near-infrared with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument. We also use proper motion measurements of the star from Hipparcos and Gaia. Results. The SPHERE data reveal a point source with a contrast of ~9 mag at a projected separation of ~235 mas. No other point sources are detected in the field of view. By jointly fitting the RV, imaging, and proper motion data, we constrain all the orbital parameters of HD72946B and assess a dynamical mass of 72.4+/-1.6 MJ and a semi-major axis of 6.45$^{+0.08}_{-0.07}$ au. Empirical comparison of its IFS spectrum to template dwarfs indicates a spectral type of L5.0+/-1.5. The J-H3 color is close to the expectations of the DUSTY models and suggests a cloudy atmosphere. Comparison with atmospheric models of the spectrophotometry suggests an effective temperature of ~1700 K. The bolometric luminosity (log(L/LS)=-4.11+/-0.10 dex) and dynamical mass of HD72946B are more compatible with evolutionary models for an age range of ~0.9-3 Gyr. The formation mechanism of the companion is currently unclear as it appears slightly away from the bulk of model predictions. HD72946B is currently the closest benchmark brown dwarf companion to a solar-type star with imaging, RV, ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| Relation: | info:eu-repo/semantics/altIdentifier/arxiv/1912.02565; ARXIV: 1912.02565 |
| DOI: | 10.1051/0004-6361/201937134 |
| الاتاحة: | https://hal.science/hal-03040498 https://hal.science/hal-03040498v1/document https://hal.science/hal-03040498v1/file/aa37134-19.pdf https://doi.org/10.1051/0004-6361/201937134 |
| Rights: | info:eu-repo/semantics/OpenAccess |
| رقم الانضمام: | edsbas.B70704B7 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1051/0004-6361/201937134 |
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