# Nearby Young, Active, Late-type Dwarfs in Gaia's First Data Release

## TL;DR

This study uses Gaia DR1 data to confirm the youth and proximity of a subset of GALNYSS stars, revealing many are nearby, young late-type stars, including previously unrecognized objects, thus expanding the known population of young stellar objects.

## Contribution

First validation of Gaia DR1 distances and ages for GALNYSS candidate young stars, identifying new nearby, young late-type stars and binaries.

## Key findings

- 19 GALNYSS stars within 120 pc are confirmed as young (10-100 Myr).
- Several hundred nearby young stars are identified in the GALNYSS sample.
- Most newly identified young stars are located north of +30° declination.

## Abstract

The Galex Nearby Young Star Survey (GALNYSS) has yielded a sample of $\sim$2000 UV-selected objects that are candidate nearby ($D \stackrel{<}{\sim}$150 pc), young (age $\sim$10--100 Myr), late-type stars. Here, we evaluate the distances and ages of the subsample of (19) GALNYSS stars with Gaia Data Release 1 (DR1) parallax distances $D \le 120$ pc. The overall youth of these 19 mid-K to early-M stars is readily apparent from their positions relative to the loci of main sequence stars and giants in Gaia-based color-magnitude and color-color diagrams constructed for all Galex- and WISE-detected stars with parallax measurements included in DR1. The isochronal ages of all 19 stars lie in the range $\sim$10--100 Myr. Comparison with Li-based age estimates indicates a handful of these stars may be young main-sequence binaries rather than pre-main sequence stars. Nine of the 19 objects have not previously been considered as nearby, young stars, and all but one of these are found at declinations north of $+$30$^\circ$. The Gaia DR1 results presented here indicate that the GALNYSS sample includes several hundred nearby, young stars, a substantial fraction of which have not been previously recognized as having ages $\stackrel{<}{\sim}$100 Myr.