Constraining the difference in convective blueshift between the components of alpha Centauri with precise radial velocities
/ Authors
D. Pourbaix, D. Pourbaix, D. Nidever, C. McCarthy, R. P. Butler, C. Tinney, G. Marcy, H. R. Jones, A. Penny, B. Carter
and 6 more authors
F. Bouchy, F. Pepe, J. Hearnshaw, J. Skuljan, D. Ramm, D. Kent
/ Abstract
New radial velocities of 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. (2001) to improve the pre- cision of the orbital parameters. The resulting masses are 1:105 0:0070 M and 0:934 0:0061 M 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 eect of the convective blueshift and the gravitational redshift is also inves- tigated and estimated to dier by 215 8m s 1 between the components. This suggests that the dierence in convective blueshift between the components is much smaller than predicted from current hydrodynamical model atmosphere calculations.
Journal: Astronomy and Astrophysics