Likely Members of the Beta Pictoris and AB Doradus Moving Groups in the North

TL;DR

This study confirms new likely members of the Beta Pictoris and AB Doradus moving groups in the northern hemisphere using high-resolution spectra, expanding the sample of young, low-mass stars for astrophysical research.

Contribution

The paper presents the first spectroscopic follow-up confirming 15 new likely group members, including binaries, and expands the known low-mass member sample of these young moving groups.

Findings

Identified 15 candidates with consistent radial velocities.

Proposed 7 Beta Pic and 8 AB Dor new members.

Discovered new spectroscopic binaries among candidates.

Abstract

We present first results from follow-up of targets in the northern hemisphere Beta Pictoris and AB Doradus moving group candidate list of Schlieder, Lepine, and Simon (2012). We obtained high-resolution, near-infrared spectra of 27 candidate members to measure their radial velocities and confirm consistent group kinematics. We identify 15 candidates with consistent predicted and measured radial velocities, perform analyses of their 6-dimensional (U,V,W,X,Y,Z) Galactic kinematics, and compare to known group member distributions. Based on these analyses, we propose that 7 Beta Pic and 8 AB Dor candidates are likely new group members. Four of the likely new Beta Pic stars are binaries; one a double lined spectroscopic system. Three of the proposed AB Dor stars are binaries. Counting all binary components, we propose 22 likely members of these young, moving groups. The majority of the proposed members are M2 to M5 dwarfs, the earliest being of type K2. We also present preliminary parameters for the two new spectroscopic binaries identified in the data, the proposed Beta Pic member and a rejected Beta Pic candidate. Our candidate selection and follow-up has thus far identified more than 40 low-mass, likely members of these two moving groups. These stars provide a new sample of nearby, young targets for studies of local star formation, disks and exoplanets via direct imaging, and astrophysics in the low-mass regime.