ICCD Speckle Observations of Binary Stars. III. A Survey for Duplicity Among High Velocity Stars
Abstract
A survey program to identify binary candidates among high-velocity dwarf stars using the GSU speckle camera has been carried out. The purposes of this study are: (1) to determine the binary frequency of the halo population to provide information on the star-formation processes in the galactic halo; and (2) to eventually derive the orbital elements of the newly discovered binaries. In this paper, the authors report speckle interferometry data that have been obtained and analyzed for a sample of 182 stars. Based on these data, ten stars are found to be binary. The authors find that their data are compatible with a total frequency for high-velocity long-period doubles as large as for low-velocity stars. Distances have been estimated for the ten binary stars using their spectroscopic parallaxes and visual magnitudes. Of these ten stars, all are within 100 pc of the Sun and eight have linear separations <20 AU. Using the mass-luminosity relation and assuming circular orbits, four stars are found to have periods less than 20 yr. These ten candidates will be monitored to determine their orbital elements.
- Publication:
-
The Astronomical Journal
- Pub Date:
- November 1987
- DOI:
- 10.1086/114569
- Bibcode:
- 1987AJ.....94.1318L
- Keywords:
-
- Binary Stars;
- Dwarf Stars;
- Orbital Elements;
- Star Formation;
- Circular Orbits;
- Interferometry;
- Speckle Patterns;
- Stellar Luminosity;
- Tables (Data);
- Astrophysics;
- STARS: BINARIES