TOI-4201: An Early M-dwarf Hosting a Massive Transiting Jupiter Stretching Theories of Core-Accretion

TL;DR

This paper confirms the discovery of a massive Jupiter-sized planet orbiting an early M dwarf, challenging existing core-accretion theories and suggesting earlier formation or alternative mechanisms like gravitational instability.

Contribution

It reports the detection and characterization of one of the most massive planets transiting an M-dwarf, providing new insights into planet formation theories.

Findings

The planet has a mass of approximately 2.59 Jupiter masses.

The planet's heavy element mass is comparable to a typical protoplanetary disk.

The discovery challenges traditional core-accretion models for planet formation.

Abstract

We confirm TOI-4201 b as a transiting Jovian mass planet orbiting an early M dwarf discovered by the Transiting Exoplanet Survey Satellite. Using ground based photometry and precise radial velocities from NEID and the Planet Finder Spectrograph, we measure a planet mass of 2.59$^{+0.07}_{-0.06}$ M$_{J}$, making this one of the most massive planets transiting an M-dwarf. The planet is $\sim$0.4\% the mass of its 0.63 M$_{\odot}$ host and may have a heavy element mass comparable to the total dust mass contained in a typical Class II disk. TOI-4201 b stretches our understanding of core-accretion during the protoplanetary phase, and the disk mass budget, necessitating giant planet formation to either take place much earlier in the disk lifetime, or perhaps through alternative mechanisms like gravitational instability.