A giant exoplanet orbiting a very low-mass star challenges planet formation models

TL;DR

This paper reports the discovery of a giant exoplanet orbiting a very low-mass star, challenging existing planet formation theories and suggesting disc instability might play a more significant role than previously believed.

Contribution

It presents the first detection of a giant planet around a very low-mass star, providing new constraints on planet formation models and challenging current theories.

Findings

Discovery of a 0.46 Jupiter mass planet around GJ 3512

High orbital eccentricity likely caused by planet-planet interactions

Challenges to core accretion models, suggesting disc instability may be more important

Abstract

Statistical analyses from exoplanet surveys around low-mass stars indicate that super-Earth and Neptune-mass planets are more frequent than gas giants around such stars, in agreement with core accretion theory of planet formation. Using precise radial velocities derived from visual and near-infrared spectra, we report the discovery of a giant planet with a minimum mass of 0.46 Jupiter masses in an eccentric 204-day orbit around the very low-mass star GJ 3512. Dynamical models show that the high eccentricity of the orbit is most likely explained from planet-planet interactions. The reported planetary system challenges current formation theories and puts stringent constraints on the accretion and migration rates of planet formation and evolution models, indicating that disc instability may be more efficient in forming planets than previously thought.