Using Photometrically-Derived Properties of Young Stars to Refine TESS's Transiting Young Planet Survey Completeness

TL;DR

This paper presents a uniform catalog of photometrically-derived properties for young stars, demonstrating that improved stellar characterization increases the detection efficiency of small transiting planets with TESS, aiding in understanding young exoplanet demographics.

Contribution

The study provides a comprehensive catalog of stellar properties for young stars and shows how these improved measurements enhance the detection of young exoplanets with TESS.

Findings

Photometrically-derived stellar properties agree well with spectroscopic data.

Enhanced stellar characterization increases detection efficiency of small planets.

Detection efficiency for sub-Neptunes/Neptunes increases by 1.5 times.

Abstract

The demographics of young exoplanets can shed light onto their formation and evolution processes. Exoplanet properties are derived from the properties of their host stars. As such, it is important to accurately characterize the host stars since any systematic biases in their derivation can negatively impact the derivation of planetary properties. Here, we present a uniform catalog of photometrically-derived stellar effective temperatures, luminosities, radii, and masses for 4,865 young (<1 Gyr) stars in 31 nearby clusters and moving groups within 200 pc. We compared our photometrically-derived properties to a subset of those derived from spectra, and found them to be in good agreement. We also investigated the effect of stellar properties on the detection efficiency of transiting short-period young planets with TESS as calculated in Fernandes et al. 2022, and found an overall increase in the detection efficiency when the new photometrically derived properties were taken into account. Most notably, there is a 1.5 times increase in the detection efficiencies for sub-Neptunes/Neptunes (1.8-6 Re) implying that, for our sample of young stars, better characterization of host star properties can lead to the recovery of more small transiting planets. Our homogeneously derived catalog of updated stellar properties, along with a larger unbiased stellar sample and more detections of young planets, will be a crucial input to the accurate estimation of the occurrence rates of young short-period planets.