Issue |
A&A
Volume 531, July 2011
|
|
---|---|---|
Article Number | A34 | |
Number of page(s) | 6 | |
Section | Stellar structure and evolution | |
DOI | https://doi.org/10.1051/0004-6361/201016373 | |
Published online | 07 June 2011 |
Dissecting the donor star in the eclipsing polar HU Aquarii
1
Leibniz-Institut für Astrophysik Potsdam (AIP),
An der Sternwarte 16,
14482
Potsdam, Germany
e-mail: aschwope@aip.de
2
Univ. of St. Andrews, School of Physics and
Astronomy, North Haugh, St.
Andrews, Fife KY16 9SS, Scotland, UK
3
Department of Physics, University of Warwick,
Coventry
CV4 7AL,
UK
4
NASA Ames Research Center, Moffett Field, CA
94035,
USA
5
Bay Area Environmental Research Institute,
560 Third St West, Sonoma, CA
95476,
USA
Received: 20 December 2010
Accepted: 3 April 2011
Medium-resolution spectroscopic observations with full phase coverage of the eclipsing
polar HU Aqr are presented. Na i absorption and Ca ii emission lines are
used to trace the secondary star. While the Na i lines seem to have contributions
from both hemispheres of the donor star, the Ca ii lines were found to originate
from the irradiated part of its surface alone. An irradiation model was applied and the
irradiation-weighted radial velocity amplitude was used to determine the mass ratio
Q = MWD/M2 = 4.58 ± 0.20.
When combined with high-speed photometric low-state eclipse light curves, the white dwarf
mass is constrained to
0.75 < MWD/M⊙ < 0.84 with
a best-fit value of
MWD = (0.80 ± 0.04) M⊙, and
M2 = (0.18 ± 0.06) M⊙ at an
orbital inclination of .
Key words: binaries: eclipsing / stars: variables: general
© ESO, 2011
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.