The close binary system EG Cephei

✍ Scribed by A. Erdem; E. Budding; O. Demircan; Ö. Lütfi Değirmenci; Ö. Gülmen; C. Sezer

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 253 KB
• Volume: 326
• Category: Article
• ISSN: 0004-6337
• DOI: 10.1002/asna.200410356

✦ Synopsis

New light curves and available times of minima of a β Lyr system EG Cep were analysed to deduce more information on the nature of the system. The main U-shaped (O -C) variation was interpreted in terms of the mass transfer and mass loss in the system. The same variation was also considered as a part of a sinusoidal variation and thus interpreted in terms of a light-time effect due to an unseen component in the system. New B and V light curves were analyzed with different fitting procedures, and there is general agreement that both stars must be very close to each other and to stability limits. A model that fits all the data well has a near main sequence primary and a secondary star that is overflowing matter towards it. This secondary is also reasonably close to main sequence conditions. The configuration thus appears to be a (relatively uncommon) 'Case A' type evolving Algol and raises interesting questions about such interactive evolution and potentially useful tests of theory.