Spectroscopic Survey of M Dwarfs within 100 Parsecs of the Sun
Abstract
We have constructed a sample of M dwarfs out to a distance of ~100 pc. This sample of 605 stars (574 M dwarfs and 31 K dwarfs) have been spectroscopically observed, yielding spectral types, radial velocities, Hα equivalent widths, and molecular band indices. Photometric observations have been compiled, with photographic plates providing RI magnitudes and JHKs magnitudes from Two Micron All Sky Survey observations. Proper motions were determined by a match to USNO-B, and distances were computed employing a spectroscopic parallax, allowing the computation of UVW space motions. These data were used to investigate the distribution of magnetically active stars within the solar neighborhood. We find that there is no statistically significant variation in activity for equidistant locations above and below the Galactic plane. We also confirm prior kinematic analysis of large samples of M dwarfs, finding that active stars form a dynamically colder population.
- Publication:
-
The Astronomical Journal
- Pub Date:
- October 2005
- DOI:
- 10.1086/444417
- Bibcode:
- 2005AJ....130.1871B
- Keywords:
-
- Galaxy: Solar Neighborhood;
- Stars: Late-Type;
- Stars: Low-Mass;
- Brown Dwarfs;
- Stars: Magnetic Fields