CAFE follow-up of TESS hot Jupiter candidates left behind: I. Five newly confirmed planets and a false positive
arXiv:2607.19756
Abstract
Hot Jupiters are key targets for understanding planet formation, migration, and atmospheres. Yet, most ground-based follow-up resources for the TESS mission are focused on confirming low-mass planet candidates, leaving many giant planets without mass determinations or definitive confirmation. We use the \cafe{} spectrograph at Calar Alto Observatory to monitor the radial velocity of stars hosting hot-Jupiter candidates that have received little follow-up, aiming to confirm their planetary nature. We present results for seven candidates. We monitored the radial velocity of TOI-603, TOI-1137, TOI-1837, TOI-2114, TOI-4492, TOI-5806, and TOI-5811, jointly modeling the CAFE radial velocities and TESS photometry to determine the nature and properties of the transiting objects. We confirm five new planets: TOI-603 b ( M, d), TOI-2114 b ( M, d), TOI-4492 b ( M, d), TOI-5806 b ( M, d), and TOI-5811 B b ( M, d). TOI-603 b lies in the "Neptune savanna", whereas the other four are hot Jupiters orbiting slightly evolved stars. We find TOI-5811.01 to be a planet transiting the nearby bound companion TOI-5811 B (hence TOI-5811 B b), and identify a stellar companion to TOI-5806 at a projected separation of 248 au, making both S-type planetary systems. TOI-1837.01 is an eclipsing binary, while TOI-1137.01 remains inconclusive. The five confirmed planets orbit bright stars (~mag), and four are excellent targets for atmospheric studies, with transmission spectroscopy metrics above 90. These results highlight the importance of intensive follow-up observations to establish the nature of transiting planet candidates.
Accepted for publication in A&A. 23 pages (12 of main text), 11 figures, 7 tables