Likely Members of the β Pictoris and AB Doradus Moving Groups in the North
Abstract
We present first results from follow-up of targets in the northern hemisphere β Pictoris and AB Doradus moving group candidate list of Schlieder et al. 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 six-dimensional (UVWXYZ) Galactic kinematics, and compare to known group member distributions. Based on these analyses, we propose that seven β Pic and eight AB Dor candidates are likely new group members. Four of the likely new β 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 β Pic member and a rejected β 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.
- Publication:
-
The Astronomical Journal
- Pub Date:
- October 2012
- DOI:
- 10.1088/0004-6256/144/4/109
- arXiv:
- arXiv:1208.0679
- Bibcode:
- 2012AJ....144..109S
- Keywords:
-
- open clusters and associations: individual: β Pic AB Dor;
- stars: pre-main sequence;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 20 pages, 5 figures, 3 tables. Accepted for publication in the Astronomical Journal. (1) Max-Planck-Institute for Astronomy, (2) Stony Brook University, (3) American Museum of Natural History