New Precision Orbits of Bright Double-lined Spectroscopic Binaries. VIII. HR 1528, HR 6993, 2 Sagittae, and 18 Vulpeculae
Abstract
Improved orbital elements for four A-star double-lined spectroscopic binaries have been determined with numerous new radial velocities. Three of the four systems, HR 1528, 2 Sge, and 18 Vul, have moderately short orbital periods of 7.05, 7.39, and 9.31 days, respectively, and also have circular or nearly circular orbits. Only HR 6993 with a period of 14.68 days has a significantly eccentric orbit. The close visual companion of 2 Sge has been detected spectroscopically, and its velocity measured. The orbital dimensions (a 1 sin i and a 2 sin i) and minimum masses (m 1 sin3 i and m 2 sin3 i) of the short-period binary components all have accuracies of 0.5% or better. We determine basic properties of the individual stars and compare them with solar-abundance evolutionary tracks to estimate their masses. Half of the eight components may be synchronously or pseudosynchronously rotating.
- Publication:
-
The Astronomical Journal
- Pub Date:
- November 2013
- DOI:
- 10.1088/0004-6256/146/5/129
- Bibcode:
- 2013AJ....146..129F
- Keywords:
-
- binaries: spectroscopic;
- stars: fundamental parameters;
- stars: individual: HR 1528 HR 6993 2 Sge 18 Vul