Spots on AG Virginis - paradigm or panacea ?
Abstract
New photometric and spectroscopic observations of the eclipsing binary AG Vir are presented. Medium-resolution spectroscopy has allowed the measurement of velocities for the secondary component for the first time. The V light curve shows many of the features seen in previous studies of this system. A full analysis of the spectroscopic and photometric data has been made which suggests that the system is either in a marginal state of conatact or a deep-contact configuration depending on the type of spot model invoked. AG Vir constitutes an excellent example of the expected manifestations of spot activity on a light curve. It also demonstrates the ease with which the spot phenomenon can be invoked to explain the appearance of a light curve and to provide conflicting results. This study shows the necessity of a more thorough investigation of this system using Doppler-imaging techniques and simultaneous infrared and optical photometry.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 1990
- Bibcode:
- 1990MNRAS.247..632B
- Keywords:
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- Astronomical Photometry;
- Astronomical Spectroscopy;
- Eclipsing Binary Stars;
- Starspots;
- Diurnal Variations;
- Electrophotometry;
- Ephemerides;
- Light Curve;
- Radial Velocity;
- Astrophysics