AAVSO: American Association of Variable Star Observers

A Photometric Study of the Contact Binary V384 Serpentis

Volume 47 number 1 (2019)

Download this article (pdf)

Edward J. Michaels
Stephen F. Austin State University, Department of Physics, Engineering and Astronomy, P.O. Box 13044, Nacogdoches, TX 75962; emichaels@sfasu.edu
Chlöe M. Lanning
Stephen F. Austin State University, Department of Physics, Engineering and Astronomy, P.O. Box 13044, Nacogdoches, TX 75962; chloelanning@gmail.com
Skyler N. Self
Stephen F. Austin State University, Department of Physics, Engineering and Astronomy, P.O. Box 13044, Nacogdoches, TX 75962; skyler.self.23@gmail.com

Abstract

In this paper we present the first photometric light curves in the Sloan g', r', and i' passbands for the contact binary V384 Ser. Photometric solutions were obtained using the Wilson-Devinney program which revealed the star to be a W-type system with a mass ratio of q = 2.65 and a f = 36% degree of contact. The less massive component was found to be about 395 K hotter than the more massive one. A hot spot was modeled on the cooler star to fit the asymmetries of the light curves. By combining our new times of minima with those found in the literature, the (O–C) curve revealed a downward parabolic variation and a small cyclic oscillation with an amplitude of 0.0037 day and a period 2.86 yr. The downward parabolic change corresponds to a long-term decrease in the orbital period at a rate of dP/dt = –3.6 × 10–8 days yr–1. The cyclic change was analyzed for the light-travel time effect that results from the gravitational influence of a close stellar companion.