Characterizing the Distribution of Parameters of Planets Found by Radial Velocity is Essential for Understanding Planet Formation and Evolution

TL;DR

Understanding the distribution of exoplanet parameters, especially their correlations with stellar properties, is crucial for testing theories of planet formation and evolution, highlighting the need for more extensive planet detection across various periods.

Contribution

The paper emphasizes the importance of characterizing exoplanet parameter distributions and advocates for increased planet discovery efforts to better understand planetary system histories.

Findings

Distribution features reveal correlations with stellar properties.

Current data are insufficient for reliable relationship analysis.

Supporting more planet discoveries can improve understanding of planet evolution.

Abstract

Features in the distribution of exoplanet parameters by period demonstrate that the distribution of planet parameters is rich with information that can provide essential guidance to understanding planet histories. Structure has been found in the counts of planet-star "objects" by period, and within these structures, there are different correlations of eccentricity with planet number, stellar metallicity, planet count density per log period, stellar multiplicity, and planet mass. These appear to change with each other, and with stellar mass, but there are too few planets to easily and reliably study these important relationships. These relationships are the bulk observables against which the theory of planet formation and evolution must be tested. The opportunity to determine the nature of the relationships of the exoplanet parameters on each other demonstrate the value of finding more planets across period ranging from days to thousands of days and beyond. We recommend support for continuing to find more planets, even giant planets, with periods up to periods of a few thousand days. We also recommend support for the study of the distribution of the many exoplanet parameters.