Orbit and atmosphere of HIP 99770 b through the eyes of VLTI/GRAVITY

作者：T. O. Winterhalder, Jens Kammerer, S. Lacour, A. Mérand, M. Nowak, T. Stolker, William O. Balmer, Gabriel-Dominique Marleau, R. Abuter, A. Amorim, R. Asensio-Torres, Jean-Philippe Berger, H. Beust, Sarah Blunt, M. Bonnefoy, H. Bonnet, M. Sadun Bordoni, G. Bourdarot, W. Brandner, F. Cantalloube, P. Caselli, Benjamin Charnay, G. Chauvin, A. Chavez, Élodie Choquet, Valentin Christiaens, Y. Clénet, V. Coudé du Foresto, A. Cridland, R. Davies, R. Dembet, Jason Dexter, A. Drescher, G. Duvert, A. Eckart, F. Eisenhauer, N. M. Förster Schreiber, P. García, R. García López, Tyler Gardner, É. Gendron, R. Genzel, S. Gillessen, J. H. Girard, S. Grant, X. Haubois, G. Heiß el, Th. Henning, Sasha Hinkley, S. Hippler, M. Houllé, Z. Hubert, L. Jocou, M. Keppler, P. Kervella, Laura Kreidberg, N. T. Kurtovic, A.-M. Lagrange, V. Lapeyrère, J.-B. Le Bouquin, D. Lutz, A.-L. Maire, F. Mang, P. Mollière, C. Mordasini, D. Mouillet, E. Nasedkin, Thomas Ott, G.P.L. Otten, C. Paladini, T. Paumard, K. Perraut, G. Perrin, N. Pourré, Laurent Pueyo, D. C. Ribeiro, Emily Rickman, Zafar Rustamkulov, J. Shangguan, Thomas Shimizu, David K. Sing, J. Stadler, O. Straub, C. Straubmeier, E. Sturm, L. J. Tacconi, E. F. van Dishoeck, A. Vigan, F. Vincent, S. D. von Fellenberg, Jason Wang, F. Widmann, J. Woillez, Ş. Yazıcı · 发表于：Astronomy and Astrophysics · 年份：2025 · DOI：10.1051/0004-6361/202554766 · 被引用次数：7 · 研究领域：Solar and Space Plasma Dynamics、Economic Growth and Productivity

Context . Inferring the likely formation channel of giant exoplanets and brown dwarf companions from orbital and atmospheric observables remains a formidable challenge. Further and more precise directly measured dynamical masses of these companions are required to inform and gauge formation, evolutionary, and atmospheric models. We present an updated study of the recently discovered companion to HIP 99770 based on observations conducted with the near-infrared interferometer VLTI/GRAVITY. Aims . Through renewed orbital and spectral analyses based on the GRAVITY data, we characterise HIP 99770 b to better constrain its orbit, dynamical mass, and atmospheric properties, as well as to shed light on its likely formation channel. Methods . Upon inclusion of the new high-precision astrometry epoch, we ran an orbit fit to further constrain the dynamical mass of the companion and the orbit solution. We also analysed the GRAVITY K-band spectrum, placing it into context with literature data, and extracting magnitude, age, spectral type, bulk properties and atmospheric characteristics of HIP 99770 b. Results . We detected the companion at a radial separation of 417 mas from its host. The new orbit fit yields a dynamical mass of 17 −5 +6 M Jup and an eccentricity of 0.31 −0.12 +0.06 . We also find that additional relative astrometry epochs in the future will not enable further constraints on the dynamical mass due to the dominating relative uncertainty on the Hipparcos- Gaia proper motion...