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Astron. Astrophys. 364, 543-551 (2000)
Long-term activity of the eclipsing binary AB Andromedae
G. Djura
evi
1,
H. Rovithis-Livaniou 2 and
P. Rovithis 3
1 Astronomical Observatory, Volgina 7, 11050 Belgrade, Yugoslavia (gdjurasevic@aob.bg.ac.yu)
2 Athens University, Department of Physics, Section of Astrophysics-Astronomy & Mechanics, Zografos, 157 84 Athens, Greece (elivan@atlas.uoa.gr)
3 Astron. Institute, National Observatory of Athens, P.O. Box 20048, 118 10 Athens, Greece
Received 5 February 1998 / Accepted 19 September 2000
Abstract
In the present study, the activity of the eclipsing binary AB And is examined by analysing the photometric data covering the period from 1968 till 1995.
The light curves corresponding to this period show significant
differences and asymmetries, which are especially conspicuous in the
height of the light-curve maxima and in the part following the
secondary maximum as well as in the depth of the primary light-curve
minimum. To explain the light asymmetries and variations, we used a
model that involves spotted regions on the components. The analysis
shows that AB And is in overcontact configuration
(![[FORMULA]](img1.gif)
). The Roche model with single
spotted areas on both components yields a good fit of the observations
for the whole set of the analysed light curves without any changes of
the basic system's parameters. This indicates that the complex nature
of the light-curve variations during the examined period can be almost
completely explained by the development and motion of the spotted
areas on the components. According to the obtained results the spotted
areas are probably formed at high latitudes and cover a significant
part of the stellar surface; the change of their locations and sizes
with time is examined.
Key words: stars: binaries:
close 
stars: binaries:
eclipsing
stars: individual:
AB And
stars: starspots
Send offprint requests to: G. Djuraevi
Contents
- 1. Introduction
- 2. Procedure of the light-curve analysis
- 3. Results
- 4. Discussion and conclusions
- Acknowledgements
- References
© European Southern Observatory (ESO) 2000
Online publication: January 29, 2001
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