RV-detected Kepler-multi Analogs Exhibit Intra-system Mass Uniformity

TL;DR

This paper demonstrates that multi-planet systems detected via Doppler velocities also show intra-system mass uniformity, which breaks down in systems with giant planets, confirming a pattern observed in transit data.

Contribution

It extends the intra-system mass uniformity observation to Doppler-detected systems, avoiding transit bias and highlighting the effect of giant planets on this pattern.

Findings

Intra-system mass uniformity is present in Doppler-detected multi-planet systems.

Mass uniformity breaks down in systems with giant planets.

Supports the idea of a common formation process for smaller planets.

Abstract

Recent work has shown that the planets in the $Kepler$ Mission's population of multi-transiting systems show surprising uniformity in both mass and radius. In this brief note, I show that this intra-system mass uniformity extends to multiple-planet systems detected with the Doppler velocity technique, thereby avoiding possible biases associated with masses determined by transit timing. I also show that intra-system mass uniformity breaks down when a system contains one or more giant planets.