AAVSO: American Association of Variable Star Observers

CCD Photometry, Light Curve Modeling, and Period Study of V573 Serpentis, a Totally Eclipsing Overcontact Binary System

Volume 49 number 2 (2021)

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Kevin B. Alton
Desert Blooms Observatory, 70 Summit Avenue, Cedar Knolls, NJ 07927; kbalton@optonline.net
Edward O. Wiley
Live Oaks Observatory, 125 Mountain Creek Pass, Georgetown, TX 78633; ewiley@suddenlink.net

Abstract

Precise time-series multi-color light curve data were acquired from V573 Ser at Desert Blooms Observatory (DBO) in 2019 and Live Oaks Observatory (LOO) in 2020. Previously, only monochromatic CCD-derived photometric data were available from automated surveys which employ sparse sampling strategies. New times-of-minimum from data acquired at DBO and LOO, along with other eclipse timings extrapolated from selected surveys, were used to generate a new linear ephemeris. Secular analyses (eclipse timing differences vs. epoch) did not reveal changes in the orbital period of V573 Ser over the past 20 years. Simultaneous modeling of multicolor light curve data during each epoch was accomplished using the Wilson-Devinney code. Since a total eclipse is observed, a unique photometrically derived value for the mass ratio (qptm) could be determined, which subsequently provided initial estimates for the physical and geometric elements of each variable system.