First VLTI/GRAVITY Observations of HIP 65426 b: Evidence for a Low or Moderate Orbital Eccentricity

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Blunt, S (Author) Other; Balmer, WO (Author) Other; Wang, JJ (Author) Other; Lacour, S (Author) Other; Petrus, S (Author) Other; Bourdarot, G (Author) Other; Kammerer, J (Author) Other; Pourré, N (Author) Other; Rickman, E (Author) Other; Shangguan, J (Author) Other; Winterhalder, T (Author) Other; Abuter, R (Author) Other; Amorim, A (Author) Other; Asensio Torres, R (Author) Other; Benisty, M (Author) Other; Berger, JP (Author) Other; Beust, H (Author) Other; Boccaletti, A (Author) Other; Bohn, A (Author) Other; Bonnefoy, M (Author) Other; Bonnet, H (Author) Other; Brandner, W (Author) Other; Cantalloube, F (Author) Other; Caselli, P (Author) Other; Charnay, B (Author) Other; Chauvin, G (Author) Other; Chavez, A (Author) Other; Choquet, E (Author) Other; Christiaens, V (Author) Other; Clénet, Y (Author) Other; du Foresto, VC (Author) Other; Cridland, A (Author) Other; Dembet, R (Author) Other; Drescher, A (Author) Other; Duvert, G (Author) Other; Eckart, A (Author) Other; Eisenhauer, F (Author) Other; Feuchtgruber, H (Author) Other; P. J. V. Garcia (Author) FEUP; Lopez, RG (Author) Other; Gendron, E (Author) Other; Genzel, R (Author) Other; Gillessen, S (Author) Other; Girard, JH (Author) Other; Haubois, X (Author) Other; Heissel, G (Author) Other; Henning, T (Author) Other; Hinkley, S (Author) Other; Hippler, S (Author) Other; Horrobin, M (Author) Other; Houllé, M (Author) Other; Hubert, Z (Author) Other; Jocou, L (Author) Other; Keppler, M (Author) Other; Kervella, P (Author) Other; Kreidberg, L (Author) Other; Lagrange, AM (Author) Other; Lapeyrère, V (Author) Other; Le Bouquin, JB (Author) Other; Leña, P (Author) Other; Lutz, D (Author) Other; Maire, AL (Author) Other; Mang, F (Author) Other; Marleau, GD (Author) Other; Mérand, A (Author) Other; Mollière, P (Author) Other; Monnier, JD (Author) Other; Mordasini, C (Author) Other; Mouillet, D (Author) Other; Nasedkin, E (Author) Other; Nowak, M (Author) Other; Ott, T (Author) Other; Otten, GPPL (Author) Other; Paladini, C (Author) Other; Paumard, T (Author) Other; Perraut, K (Author) Other; Perrin, G (Author) Other; Pfuhl, O (Author) Other; Pueyo, L (Author) Other; Rameau, J (Author) Other; Rodet, L (Author) Other; Rustamkulov, Z (Author) Other; Shimizu, T (Author) Other; Sing, D (Author) Other; Stolker, T (Author) Other; Straubmeier, C (Author) Other; Sturm, E (Author) Other; Tacconi, LJ (Author) Other; van Dishoeck, EF (Author) Other; Vigan, A (Author) Other; Vincent, F (Author) Other; Ward Duong, K (Author) Other; Widmann, F (Author) Other; Wieprecht, E (Author) Other; Wiezorrek, E (Author) Other; Woillez, J (Author) Other; Yazici, S (Author) Other; Young, A (Author) Other

Journal

Title: Astronomical Journal

Vol. 166

Final page: 257

ISSN: 0004-6256

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Other information

Authenticus ID: P-00Z-F30

DOI: 10.3847/1538-3881/ad06b7

Abstract (EN): Giant exoplanets have been directly imaged over orders of magnitude of orbital separations, prompting theoretical and observational investigations of their formation pathways. In this paper, we present new VLTI/GRAVITY astrometric data of HIP 65426 b, a cold, giant exoplanet which is a particular challenge for most formation theories at a projected separation of 92 au from its primary. Leveraging GRAVITY's astrometric precision, we present an updated eccentricity posterior that disfavors large eccentricities. The eccentricity posterior is still prior dependent, and we extensively interpret and discuss the limits of the posterior constraints presented here. We also perform updated spectral comparisons with self-consistent forward-modeled spectra, finding a best-fit ExoREM model with solar metallicity and C/O = 0.6. An important caveat is that it is difficult to estimate robust errors on these values, which are subject to interpolation errors as well as potentially missing model physics. Taken together, the orbital and atmospheric constraints paint a preliminary picture of formation inconsistent with scattering after disk dispersal. Further work is needed to validate this interpretation. Analysis code used to perform this work is available on GitHub: https://github.com/sblunt/hip65426.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 20