Details

Autor(en) / Beteiligte

• Osborne, H. L.M.
• Van Eylen, V.
• Goffo, E.
• Gandolfi, D.
• Nowak, G.
• Persson, C. M.
• Livingston, J.
• Weeks, A.
• Palle, E.
• Luque, R.
• Hellier, C.
• Carleo, I.
• Redfield, S.
• Hirano, T.
• Gili, M. Garbaccio
• Alarcon, J.
• Barragan, O.
• Casasayas-Barris, N.
• Díaz, M. R.
• Esposito, M.
• Knudstrup, E.
• Jenkins, J. S.
• Murgas, F.
• Orell-Miquel, J.
• Rodler, F.
• Serrano, L.
• Stangret, M.
• Albrecht, S. H.
• Alqasim, A.
• Cochran, W. D.
• Deeg, H. J.
• Fridlund, M.
• Hatzes, A. P.
• Korth, J.
• Lam, K. W.F.

Titel

TOI-544 b:ã potential water-world inside the radius valley inã two-planet system

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2024-02, Vol.527 (4), p.11138

Erscheinungsjahr

2024

Link zum Volltext

Quelle

EZB*

Beschreibungen/Notizen

• We report on the precise radial velocity follow-up of TOI-544 (HD 290498),ã bright K star ( V = 10.8), which hostsã small transiting planet recently disco v ered by the Trãnsiting Exoplanet Survey Satellite (TESS) . We collected 122 high-resolution High Accuracy Radial velocity Planet Searcher (HARPS)ãnd HARPS-N spectra to spectroscopically confirm the transiting planetãnd measure its mass. The nearly 3-yr baseline of our follow-upãllowed us to unveil the presence ofãnãdditional, non-transiting, longer-period companion planet. We derivedã radiusãnd mass for the inner planet, TOI-544 b, of 2.018 ±0.076 R⊙and 2.89 ±0.48 M⊙, respectively, which givesã bulk density of 1 . 93 + 0 . 30 -0 . 25 g cm -3 . TOI-544 c hasã minimum mass of 21.5 ±2.0 M⊙and orbital period of 50.1 ±0.2 d. The low density of planet-b implies that it has eitherãn Earth-like rocky core withã hydrogenãtmosphere, orã composition which harboursã significant fraction of water. The composition interpretation is degenerate depending on the specific choice of planet interior models used. Additionally, TOI-544 b hasãn orbital period of 1.55 dãnd equilibrium temperature of 999 ±14 K, placing it within the predicted location of the radius valley, where few planetsãre expected. TOI-544 b isã top target for futureãtmospheric observations, for example with JWST , which would enable better constraints of the planet composition.