A Photometric Study of V508 Cygni

The Behlen observatory 0.76 m telescope CCD photometer has been used to obtain nearly 700 observations of the short period eclipsing binary V508 Cyg. These observations were done using V and R bandpass filters on 9 nights in 1992. Previously published light elements and the present eight determinations of eclipse timings are used to determine a new epoch and a more accurate orbital period of 0.7796587 days. The photometric observations and solutions which have been obtained with the 1993 version of the Wilson-Devinney model show that V508 Cyg is a W UMa type contact binary system. Analyses give two possible contact solutions of different mass ratios (q = m₂/m₁, where star 1 is eclipsed at the primary minimum). One with q =0.44 gives an A-type W UMa system configuration, while the other with q =1.19 gives a W-type W UMa system configuration. V508 Cyg does not have a spectral classification, however, based on the color (V-R =0.566 Schmidt 1991b), we estimate it to be US. Generally W UMa systems with spectral-type US have periods ranging from 0.25 to 0.5 days. The considerably longer period of V508 Cyg suggests that it may be an evolved contact system with case B mass transfer. Both solutions indicate that the two components have similar temperature and luminosities. It is suspected that this system may be a double lined spectroscopic binary. Therefore it is recommended that spectroscopic observations of V508 Cyg be obtained so that a unique mass ratio can be established.