The rotational velocity of the sdOB primary of the eclipsing binary system LB 3459 (AA Dor)
arXiv:astro-ph/0301103 · doi:10.1051/0004-6361:20021883
Abstract
We present an analysis of the rotational velocity of the primary of LB 3459 based on 107 new high-resolution and high-S/N ESO VLT UVES spectra. 105 of them cover a complete orbital period (0.26 d) of this binary system. We have determined an orbital period of P = 22600.702 +/- 0.005 sec, a radial velocity amplitude of A_1 = 39.19 +/- 0.05 km/sec, and T_0 = 2451917.152690 +/- 0.000005. From simulations of the He II 4686A line profile (based on NLTE model atmosphere calculations), we derive v_rot = 47 +/- 5 km/sec. We present an animation which shows the orbital movement of the binary system, its synthetic lightcurve, and compares the phase-dependent variation of the predicted with the observed He II 4686A line profile. The radius of the cool component is almost the same size like Jupiter but its mass is about 70 times higher than Jupiter's mass. Thus, from its present mass (M_2 = 0.066 M_sun), the secondary of LB 3459 lies formally within the brown-dwarf mass range (0.013 - 0.08 M_sun). It might be a former planet which has survived the previous common-envelope phase and even has gained mass.
arXiv comment7 pages, 11 Postscript figures, to appear in A&A
Cited by in corpus (13)
- Observational Evidence for Tidal Interaction in Close Binary Systems
- Rotation Velocities of Red and Blue Field Horizontal-Branch Stars
- The binary properties of the pulsating subdwarf B eclipsing binary PG 1336-018 (NY Vir)
- Hot subdwarf stars in close-up view I. Rotational properties of subdwarf B stars in close binary systems and nature of their unseen companions
- The Orbit and Occultations of KH 15D
- Six detached white-dwarf close binaries
- Stellar wind models of subluminous hot stars
- New VI photometry of the sdOB binary AA Dor and an improved photometric model
- Looking at the bright side - The story of AA Dor as revealed by its cool companion
- FUSE spectroscopy of sdOB primary of the post common-envelope binary LB 3459 (AA Dor)
- The mass ratio and the orbital parameters of the sdOB binary AA Doradus
- Space observations of AA Doradus provide consistent mass determinations. New HW-Vir systems observed with TESS
- A Dor - An Eclipsing Subdwarf - Brown Dwarf Binary