2026/07/22 by J. Lillo-Box, C. Cifuentes, O. Balsalobre-Ruza +56
#astro-ph.EP
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 (33.0+6.5-6.2 M⊕, 16.2 d), TOI-2114 b (1.01+0.14-0.12 M\rm Jup, 6.2 d), TOI-4492 b (5.92+0.67-0.64 M\rm Jup, 4.4 d), TOI-5806 b (2.77+0.34-0.32 M\rm Jup, 3.2 d), and TOI-5811 B b (0.81+0.11-0.10 M\rm Jup, 6.3 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 (\rm G=8.6-10.2~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.