A New Method to Identify Nearby, Young, Low-mass Stars

TL;DR

This paper introduces a new photometric method using GALEX ultraviolet data to identify young, low-mass stars within 150 parsecs, successfully finding numerous candidates and confirming youth indicators spectroscopically.

Contribution

The study presents a novel technique combining UV and optical/IR data to efficiently identify young, late-type stars, expanding the toolkit for nearby young star detection.

Findings

Identified 54 candidate young stars near TW Hya and Scorpius-Centaurus.

Spectroscopy confirmed lithium absorption in at least 17 M-type stars.

Method leverages GALEX UV data, applicable to large sky areas.

Abstract

We describe a new method to identify young, late-type stars within ~150 pc of the Earth that employs visual or near-infrared data and the GALEX GR4/5 database. For spectral types later than K5, we demonstrate that the ratio of GALEX near-ultraviolet (NUV) to visual and near-IR emission is larger for stars with ages between 10 and 100 Myr than for older, main sequence stars. A search in regions of the sky encompassing the TW Hya and Scorpius-Centaurus Associations has returned 54 high-quality candidates for followup. Spectroscopic observations of 24 of these M1-M5 objects reveal Li 6708 angstrom absorption in at least 17 systems. Because GALEX surveys have covered a significant fraction of the sky, this methodology should prove valuable for future young star studies.