CAFE follow-up of TESS hot Jupiter candidates left behind: I. Five newly confirmed planets and a false positive

arXiv:2607.19756 · astro-ph.EP · Submitted 2026-07-22 · Read on arXiv

J. Lillo-Box, C. Cifuentes, O. Balsalobre-Ruza, B. Montesinos, D. Latham, K. A. Collins, D. Ciardi, G. Hébrard, S. W. Yee, E. W. Guenther, H. Bouy, J. N. Winn, S. B. Howell, C. Ziegler, M. E. Everett, B. Safonov, F. Murgas, N. Narita, L. D. Nielsen, A. Abreu, J. Aceituno, J. F. Agüí Fernández, M. Azzaro, D. Barrado, P. Benni, A. Bieryla, A. Chontos, C. A. Clark, E. Delgado-Mena, S. J. Deveny, R. Forés-Toribio, J. Flores-Martín, A. Garmash, S. Góngora, J. D. Hartman, C. Haukes, N. Heidari, I. J. Helm, J. F. Kielkopf, J. Köhler, C. Littlefield, M. B. Lund, B. Massey, A. Masson, J. McCormac, M. Morales-Calderón, M. Mori, J. A. Muñoz, E. Pallé, P. Plavchan, M. Reefe, J. E. Schlieder, G. Srdoc, C. Stockdale, J. C. van Eyken, R. G. West, F. P. Wilkin, J. Wittrock, D. -V. Zora

astro-ph.EP

Submitted: 2026-07-22

Comments: Accepted for publication in A&A. 23 pages (12 of main text), 11 figures, 7 tables

Code: https://github.com/jlillo/tpfplotterhttps:

Project page: https://lightkurve.github.io/lightkurve/2

License: http://creativecommons.org/licenses/by-nc-sa/4.0/

The gist: Hot Jupiters are key targets for understanding planet formation, migration, and atmospheres.

Terminology

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 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 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). 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 (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.

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