Three Warm Jupiters orbiting TOI-6628, TOI-3837, TOI-5027 and one sub-Saturn orbiting TOI-2328

TL;DR

This paper reports the discovery and detailed characterization of four new exoplanets, including three warm Jupiters and one sub-Saturn, using TESS data combined with follow-up observations, revealing their orbital and physical properties.

Contribution

The study provides new detailed measurements of four exoplanets, including their masses, radii, and eccentricities, and supports the core accretion model of planet formation.

Findings

TOI-6628b has a highly eccentric orbit with e=0.667.

All four planets have orbital periods above 10 days.

Interior models suggest rocky-icy cores with H/He envelopes.

Abstract

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 lightcurves of the Transiting Exoplanet Survey Satellite \textbf{(TESS)} space mission. By combining TESS lightcurves with ground-based photometric and spectroscopic follow-up observations we confirm the planetary nature of the observed transits and radial velocity variations. TOI-6628~$b$ has a mass of 0.75$\pm$0.06~$M_\mathrm{J}$, a radius of 0.98$\pm$0.05~$R_J$ and is orbiting a metal-rich star with a period of 18.18424$\pm{0.00001}$ days and an eccentricity of 0.667$\pm0.016$, making it one of the most eccentric orbits of all known warm giants. TOI-3837~$b$ has a mass of 0.59$\pm$0.06~$M_\mathrm{J}$, a radius of 0.96$\pm$0.05~$R_J$ and orbits its host star every 11.88865$\pm$0.00003~days, with a moderate eccentricity of 0.198$^{+0.046}_{-0.058}$. With a mass of 2.01$\pm$0.13~$M_\mathrm{J}$ and a radius of 0.99$^{+0.07}_{-0.12}$ $R_J$, TOI-5027~$b$ orbits its host star in an eccentric orbit with $e$~=~0.395$^{+0.032}_{-0.029}$ every 10.24368$\pm{0.00001}$~days. TOI-2328~$b$ is a Saturn-like planet with a mass of 0.16$\pm$0.02~$M_\mathrm{J}$ and a radius of 0.89$\pm$0.04~$R_J$, orbiting its host star in a nearly circular orbit with $e$~=~0.057$^{+0.046}_{-0.029}$ at an orbital period of 17.10197$\pm{0.00001}$ days. All four planets have orbital periods above 10 days, and our planet interior structure models are consistsent a rocky-icy core with a H/He envelope, providing evidence supporting the core accretion model of planet formation for this kind of planets.