BANYAN. XII. New Members of Nearby Young Associations from Gaia-Tycho Data

TL;DR

This paper uses Gaia-Tycho data and an updated Bayesian software to identify and confirm new members of nearby young stellar associations within 150 parsecs, enhancing the understanding of their composition and distribution.

Contribution

Introduces an improved Bayesian membership probability method incorporating Gaia-2MASS data, identifying new bona fide and candidate members of young stellar associations within 150 pc.

Findings

Identified 32 new bona fide members of young associations.

Confirmed membership of 66 previously known candidates.

Discovered 219 new candidate members, mostly lacking radial velocity data.

Abstract

We present a search for stellar members of young associations within 150 pc of the Sun based on Gaia-Tycho and an updated version of the BANYAN $\Sigma$ software to determine Bayesian membership probabilities that includes Gaia-2MASS color-magnitude diagrams. We identify 32 new F0-M3-type bona fide members of the 10-200 Myr-old Sco-Cen, Carina, Tucana-Horologium, Columba and Octans associations and the AB Doradus, $\beta$ Pictoris and Carina-Near moving groups. These new bona fide members have measurements of their full kinematics and literature data consistent with a young age. We also confirm the membership of 66 previously known candidate members using their Gaia-Tycho trigonometric distances or new literature radial velocities, and identify 219 additional new candidate members, most of which do not yet have a radial velocity measurement. This work is the first step towards a completeness-corrected survey of young association members based on Gaia-DR2 in the near future.