Volume 417, Number 3, April III 2004
|Page(s)||1083 - 1092|
|Section||Stellar structure and evolution|
|Published online||26 March 2004|
Asiago eclipsing binaries program
I. V432 Aurigae
Dipartimento di Astronomia dell'Università di Padova, Osservatorio Astrofisico, 36012 Asiago (VI), Italy
2 Osservatorio Astronomico di Padova, Sede di Asiago, 36012 Asiago (VI), Italy
3 CISAS, Centro Interdipartimentale Studi ed Attività Spaziali dell'Università di Padova
4 Via Filzi 9, 38034 Cembra (TN), Italy
5 University of Ljubljana, Department of Physics, Jadranska 19, 1000 Ljubljana, Slovenia
6 Physics and Astronomy Department, University of Calgary, Calgary T2N 1N4, Canada
Corresponding author: U. Munari, firstname.lastname@example.org
Accepted: 7 January 2004
The orbit and physical parameters of the previously unsolved eclipsing binary V432 Aur, discovered by Hipparcos, have been derived with errors better than 1% from extensive Echelle spectroscopy and B, V photometry. Synthetic spectral analysis of both components has been performed, yielding Teff and in close agreement with the orbital solution, a metallicity [ ] = -0.6 and rotational synchronization for both components. Direct comparison on the theoretical plane with the Padova evolutionary tracks and isochrones for the masses of the two components (1.22 and 1.08 ) provides a perfect match and a 3.75 Gyr age. The more massive and cooler component is approaching the base of the giant branch and displays a probable pulsation activity with an amplitude of = 0.075 mag and Δrad.vel. = 1.5 km s-1. With a Teff = 6080 K it falls to the red of the nearby instability strip populated by δ Sct and γ Dor types of pulsating variables. Orbital modeling reveals a large and bright surface spot on it. The pulsations activity and the large spot(s) suggest the presence of macro-turbulent motions in its atmosphere. They reflect in a line broadening that at cursory inspection could be taken as indication of a rotation faster than synchronization, something obviously odd for an old, expanding star.
Key words: stars: fundamental parameters / stars: binaries: spectroscopic / stars: binaries: eclipsing / stars: oscillations / stars: individual: V432 Aur / stars: starspots
© ESO, 2004
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.