Constraining the difference in convective blueshift between the components of alpha Centauri with precise radial velocities
Abstract
New radial velocities of alpha Cen A & B obtained in the framework the Anglo-Australian Planet Search programme as well as in the CORALIE programme are added to those by Endl et al. (\cite{Endl-2001:a}) to improve the precision of the orbital parameters. The resulting masses are 1.105+/-0.0070 Msun and 0.934+/-0.0061 Msun for A and B respectively. The factors limiting how accurately these masses can be derived from a combined visual-spectroscopic solution are investigated. The total effect of the convective blueshift and the gravitational redshift is also investigated and estimated to differ by 215 +/- 8 m s-1 between the components. This suggests that the difference in convective blueshift between the components is much smaller than predicted from current hydrodynamical model atmosphere calculations.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 2002
- DOI:
- 10.1051/0004-6361:20020287
- arXiv:
- arXiv:astro-ph/0202400
- Bibcode:
- 2002A&A...386..280P
- Keywords:
-
- Stars: Binaries: General;
- Stars: Individual: Alpha Cen;
- Methods: Data Analysis;
- Astrophysics
- E-Print:
- 6 pages, 2 figures. To appear in A&