2025A&A...694A.268T

We report the discovery and characterization of three new transiting giant planets orbiting TOI-6628, TOI-3837, and TOI-5027 and one new warm sub-Saturn orbiting TOI-2328, whose transits events were detected in the light curves of the Transiting Exoplanet Survey Satellite (TESS) space mission. By combining TESS light curves with ground-based photometric and spectroscopic followup observations, we confirm the planetary nature of the observed transits and radial velocity variations. TOI-6628 b has a mass of 0.74±0.06 M_J and a radius of 0.98_–0.05^+0.06R_J and orbits a metal-rich star with a period of 18.18424 ± 0.00001 days and an eccentricity of 0.670_–0.016^+0.015, making it one of the most eccentric orbits of all known warm giants. TOI-3837 b has a mass of 0.59±0.05 M_J and a radius of 0.97_–0.06^+0.05R_J and orbits its host star every 11.88865 ± 0.00003 days, with a moderate eccentricity of 0.221_–0.046^+0.042. With a mass of 2.02±0.13 M_J and a radius of 0.96_–0.06^+0.05R_J, TOI-5027 b orbits its host star in an eccentric orbit with e = 0.385_–0.026^+0.025 every 10.24368±0.00001 days. TOI-2328 b is a Saturn-like planet with a mass of 0.16±0.02 M_J and a radius of 0.89_–0.05^+0.04R_J; it orbits its host star in a nearly circular orbit with e = 0.057_–0.029^+0.046 at a period of 17.10197±0.00001 days. All four planets have orbital periods above ten days, and our planet's interior structure models are consistent with a rocky-icy core with an H/He envelope, providing evidence supporting the core-accretion model of planet formation for this kind of planet.