CAFE follow-up of TESS hot Jupiter candidates left behind

Context . Hot Jupiters are key targets for understanding planet formation, migration, and atmospheres. Yet most of the ground-based observational resources for the follow-up of the TESS mission are focused on the confirmation of low-mass planet candidates. This leaves the more massive planets, such as hot Jupiters, without mass determinations and definitive confirmations. Aims . We used the CAFE 2 spectrograph at the Calar Alto Observatory to monitor the radial velocity of stars with hot-Jupiter candidates that have been left behind by follow-up efforts with the goal of confirming their planetary nature. Here, we present the results for seven candidates. Methods . We monitored the radial velocity of the seven candidate host stars TOI-603, TOI-1137, TOI-1837, TOI-2114, TOI-4492, TOI-5806, and TOI-5811. Each hosts a hot-Jupiter candidate detected by the TESS mission. We characterized these stars and jointly modeled the CAFE 2 RVs and the TESS photometric data to unravel the nature of the transiting objects and to infer their properties. Results . The objects we confirmed to be new planets are TOI-603 b (mass 33.0 +6.5 −6.2 M ⊕ , period 16.2 d); TOI-2114 b (1.01 +0.14 −0.12 M Jup , 6.2 d); TOI-4492 b (5.92 +0.67 −0.64 M Jup , 4.4 d); TOI-5806 b (2.77 +0.34 −0.32 M Jup , 3.2 d); and TOI-5811 B b (0.81 +0.11 −0.10 M Jup , 6.3 d). Based on their masses and periods, TOI-603 b is a member of the “Neptune savanna”, while TOI-2114 b, TOI-4492 b, TOI-5806 b, and TOI-5811 B b are hot Jupiters orbiting slightly evolved stars. We found the candidate TOI-5811.01 to actually be a planet orbiting the nearby bound companion TOI-5811 B. We also identified a bound stellar companion to TOI-5806 at a projected separation of 248 au, thus both form satellite-type planetary systems. As for the two remaining candidates, TOI-1837.01 is definitely an eclipsing binary, while the nature of TOI-1137.01 remains indeterminate. Conclusions . The five newly confirmed planets orbit relatively bright stars (G = 8.6–10.2 mag), and four of them are excellent candidates for atmospheric studies (with transmission spectroscopy metrics exceeding 90 for TOI-603 b, TOI-2114 b, TOI-5806 b, and TOI-5811 B b). The complex configurations of all of these systems underscore the need for intensive follow-up efforts to clarify the nature of transiting planet candidates.