We present the detection and characterization of TOI-4994b (TIC 277128619b), a warm Saturn-sized planet discovered by the NASA Transiting Exoplanet Survey Satellite (TESS). TOI-4994b transits a G-type star (V = 12.6 mag) with a mass, radius, and effective temperature of $M_{ \star} =1.005^{ +0.064}_{ -0.061} M_{ \odot}$, $R_{ \star} = 1.055^{ +0.040}_{ -0.037} R_{ \odot}$, and $T_{ \rm eff} = 5640 \pm 110$ K. We obtained follow-up ground-based photometry from the Las Cumbres Observatory (LCO) and the Antarctic Search for Transiting ExoPlanets (ASTEP) telescopes, and we confirmed the planetary nature of TOI-4994b with multiple radial velocity observations from the PFS, CHIRON, HARPS, FEROS, and CORALIE instruments. From a global fit to the photometry and radial velocities, we determine that TOI-4994b is in a 21.5-day, eccentric orbit ($e = 0.32 \pm 0.04$) and has a mass of $M_{ P}= 0.280^{ +0.037}_{ -0.034} M_{ J}$, a radius of $R_{ P}= 0.762^{ +0.030}_{ -0.027}R_{ J}$, and a Saturn-like bulk density of $\rho_{ p} = 0.78^{ +0.16}_{ -0.14}$ $\rm g/cm^3$. We find that TOI-4994 is a potentially viable candidate for follow-up stellar obliquity measurements. TOI-4994b joins the small sample of warm Saturn analogs and thus sheds light on our understanding of these rare and unique worlds.
Categories: astro-ph.EP