On the Semimajor Axis Distribution of Extrasolar Gas Giant Planets: Why Hot Jupiters Are Rare Around High-Mass Stars

TL;DR

This paper uses Monte Carlo simulations to demonstrate that the shorter gas disk lifetimes around high-mass stars explain the scarcity of hot Jupiters in such systems, aligning with observed planetary distributions.

Contribution

It introduces a stellar-mass dependent gas disk lifetime model that reproduces the observed semimajor axis distribution of giant exoplanets, especially the rarity of hot Jupiters around high-mass stars.

Findings

Shorter gas disk lifetimes around high-mass stars lead to fewer close-in giant planets.

The model reproduces observed planetary semimajor axis distributions.

Planet formation and migration are influenced by stellar mass-dependent disk lifetimes.

Abstract

Based on a suite of Monte Carlo simulations, I show that a stellar-mass dependent lifetime of the gas disks from which planets form can explain the lack of hot Jupiters/close-in giant planets around high-mass stars and other key features of the observed semimajor axis distribution of radial velocity-detected giant planets. Using reasonable parameters for the Type II migration rate, regions of planet formation, and timescales for gas giant core formation, I construct synthetic distributions of jovian planets. A planet formation/migration model assuming a stellar mass-dependent gas disk lifetime reproduces key features in the observed distribution by preferentially stranding planets around high-mass stars at large semimajor axes.