TOI-2379 b and TOI-2384 b: two super-Jupiter mass planets transiting low-mass host stars

TL;DR

This paper reports the discovery and characterization of two super-Jupiter mass planets orbiting low-mass M dwarf stars, providing new insights into giant planet formation around such stars.

Contribution

First detection of super-Jupiter planets transiting early M dwarf stars, with detailed mass and radius measurements, expanding knowledge of planet formation in low-mass stellar environments.

Findings

TOI-2379 b has a 5.469-day orbit, 5.76 M_J, and 1.046 R_J.

TOI-2384 b has a 2.136-day orbit, 1.966 M_J, and 1.025 R_J.

These planets have the highest and third highest planet-to-star mass ratios among low-mass host stars.

Abstract

Short-period gas giant planets have been shown to be significantly rarer for host stars less massive than the Sun. We report the discovery of two transiting giant planets - TOI-2379 b and TOI-2384 b - with low-mass (early M) host stars. Both planets were detected using TESS photometry and for both the transit signal was validated using ground based photometric facilities. We confirm the planetary nature of these companions and measure their masses using radial velocity observations. We find that TOI-2379 b has an orbital period of 5.469 d and a mass and radius of $5.76\pm0.20$ M$_{J}$ and $1.046\pm0.023$ R$_{J}$ and TOI-2384 b has an orbital period of 2.136 d and a mass and radius of $1.966\pm0.059$ M$_{J}$ and $1.025\pm0.021$ R$_{J}$. TOI-2379 b and TOI-2384 b have the highest and third highest planet-to-star mass ratios respectively out of all transiting exoplanets with a low-mass host star, placing them uniquely among the population of known exoplanets and making them highly important pieces of the puzzle for understanding the extremes of giant planet formation.