Cool Young Stars in the Northern Hemisphere: Beta Pictoris and AB Doradus Moving Group Candidates

TL;DR

This paper identifies 204 candidate young, low-mass stars in the northern hemisphere as potential members of the Beta Pictoris and AB Doradus moving groups using proper motion and activity indicators, aiding future astrophysical studies.

Contribution

It introduces a new candidate selection method combining proper motion and activity indicators, and provides a prioritized list of potential group members for follow-up observations.

Findings

Identified 8 likely new members of the groups.

Found two likely Beta Pictoris group members, including a late-K and an early-M dwarf.

Discovered six probable AB Doradus group members, including a triple system and potential brown dwarfs.

Abstract

As part of our continuing effort to identify new, low-mass members of nearby, young moving groups (NYMGs), we present a list of young, low-mass candidates in the northern hemisphere. We used our proven proper motion selection procedure and ROSAT-X-ray and GALEX-UV activity indicators to identify 204 young stars as candidate members of the Beta Pictoris and AB Doradus NYMGs. Definitive membership assignment of a given candidate will require a measurement of its radial velocity and distance. We present a simple system of indices to characterize the young candidates and help prioritize follow up observations. New group members identified in this candidate list will be high priority targets for: 1) exoplanet direct imaging searches, 2) the study of post-T-Tauri astrophysics, 3) understanding recent local star formation, and 4) the study of local galactic kinematics. Information available now allows us to identify 8 likely new members in the list. Two of these, a late-K and an early-M dwarf, we find to be likely members of the Beta Pic group. The other six stars are likely members of the AB Dor moving group. These include an M dwarf triple system, and three very cool objects that may be young brown dwarfs, making them the lowest-mass, isolated objects proposed in the AB Dor moving group to date.