Doppler confirmation of TESS planet candidate TOI-1408.01: grazing transit and likely eccentric orbit
Abstract
We report an independent Doppler confirmation of the TESS planet candidate orbiting an F-type main-sequence star TOI-1408 located 140 pc away. We present a set of radial velocities obtained with a high-resolution fibre-optic spectrograph FFOREST mounted at the SAO RAS 6-m telescope (BTA-6). Our self-consistent analysis of these Doppler data and TESS photometry suggests a grazing transit such that the planet obscures its host star by only a portion of the visible disc. Because of this degeneracy, the radius of TOI-1408.01 appears ill-determined with lower limit about ~1 RJup, significantly larger than in the current TESS solution. We also derive the planet mass of 1.69 ± 0.20 MJup and the orbital period ~4.425 d, thus making this object a typical hot Jupiter, but with a significant orbital eccentricity of 0.259 ± 0.026. Our solution may suggest that the planet is likely to experience a high tidal eccentricity migration at the stage of intense orbital rounding, or may indicate possible presence of other unseen companions in the system, yet to be detected.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2023
- DOI:
- 10.1093/mnrasl/slad127
- arXiv:
- arXiv:2309.03009
- Bibcode:
- 2023MNRAS.526L.111G
- Keywords:
-
- techniques: radial velocities;
- techniques: spectroscopic;
- planets and satellites: detection;
- stars: individual: TOI-1408;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 5 pages, 3 figures