M. Battley, M. Lafarga, E. Gillen, M. Lendl, S. Ulmer-Moll, C. S. K. Ho, E. Marfil, S. G. Sousa, Y. G. C. Frensch, D. Veras, F. Bouchy, Y. Carteret, I. J. M. Crossfield, T Fairnington, M. Houelle, D. Huber, M. Jafariyazani, L. Parc, D. J. Radford, T. G. Tan, S. Tavella, R. A. Wittenmyer, D. Wright, G. Zhou
Abstract
Studying the evolution of hot Jupiters requires a sample of well-characterized systems across all evolutionary states. We present three new gas giant exoplanets around stars approaching the end of the main sequence, a comparatively unexplored epoch of hot Jupiter evolution. These planets were discovered by TESS before being vetted and confirmed through dedicated spectroscopic follow-up programmes by Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs, CORALIE, and MINERVA-Australis. TOI-3664 b has a period of 3.30 d, a radius of 1.22 +/- 0.03 R-Jup, and a mass of 0.36 +/- 0.12 M-Jup. TOI-4034 b is a short-period hot Jupiter with a period of 1.80 d, a radius of 1.58 +/- 0.02 R-Jup, and a mass of 0.87 +/- 0.16 MJup. Meanwhile TOI-6564 b has a period of 3.99 d, radius of 1.46 +/- 0.02 R-Jup, and mass of 0.70 +/- 0.07 M-Jup. All three planets have radii larger than Jupiter but sub-Jupiter masses, in line with slight inflation as their hosts increase in luminosity towards the end of the main sequence. These exoplanets' low densities and hosts' advanced evolutionary states make them interesting planets with which to study the later stages of hot Jupiter evolution. Careful analysis was undertaken to determine the ages of each system, considering astrometry, gyrochronology, stellar isochrones, and lithium abundance, yielding ages of 9.0(+2.4) (-2.1), 5.7 +/- 0.5, and 4.0 +/- 1.0 Gyr for TOI-3664, TOI-4034, and TOI-6564, respectively, yet each system has a similar evolutionary state because of their differing stellar masses (0.98 +/- 0.03, 1.19(+0.13) (-0.03), and 1.18(+0.16) M--0.03 (& lowast;)). These three planets add more steps to the 'age-ladder' of exoplanetary evolution, building towards the community's goal of understanding how planets evolve over time.
Keywords
planets and satellites: detection / planets and satellites: gaseous planets / planets and satellites: individual: TOI-3664 b / planets and satellites: individual: TOI-4034 b / planets and satellites: individual: TOI-6564 b
Monthly Notices of the Royal Astronomical Society
Volume 549, Issue stag1053, Page 24
2026 July
