AAVSO: American Association of Variable Star Observers

Apsidal Motion Analysis of the Eccentric Eclipsing Binary V1103 Cassiopeiae (Abstract)

Volume 47 number 1 (2019)

Gary Billings
P.O. Box 263, Rockyford, Alberta T0J 2R0, Canada; obs681@gmail.com


(Abstract only) The Algol-type eclipsing binary system V1103 Cas was discovered by Otero et al. (2006), and identified as an eccentric system with period 6.1772 days. I observed it on multiple nights from 2012 to 2017, and found the primary and secondary eclipses to be of unequal depth and duration. The secondary eclipse is displaced from phase 0.5, and that displacement is slowly varying. Differential V-filtered lightcurves were modeled (using binarymaker3) to determine the eccentricity (0.27) and inclination (87.5 degrees) of the system. These parameters, and 10 times of minima, were used to determine the apsidal rotation period (748 years), using the method described by Lacy (1992). The presentation will include material showing how the eclipse widths and timing will vary through the apsidal period.