Photometric Analyses and Spectral Identification of the Early-Spectral Type W UMa Contact Binary V444 Andromedae
Ronald G. Samec
Faculty Research Associate, Pisgah Astronomical Research Institute, One Pari Drive, Rosman, NC 28772
Russell Robb
University of Victoria, Department of Physics and Astronomy, P.O. Box 3055, Station CSC, Victoria, BC V8W 3P6, Canada; and Guest Observer, Dominion Astrophysical Observatory
Danny R. Faulkner
University of South Carolina, 476 Hubbard Drive, Lancaster, SC 29720
Walter Van Hamme
Florida International University, Department of Physics, 11200 SW 8th Street, Miami, FL 33199
Received October 31, 2014; revised December 9, 2014; accepted December 9, 2014
Abstract
Presented here are the first precision UBVRcIc light curves, synthetic light curve solutions, a period study, and spectrum for V444 Andromedae, an F0V contact W UMa binary. Observations were taken with the Lowell Observatory 0.81-m reflector during 28 through 30 September 2012. From our period study we determined a linear ephemeris showing that the period has been stable over the past 9.6 years (~7,500 orbits). The period during this interval is 0.46877942 d. After a q-search, the lowest residual mass ratio was found to be 0.48 with a Roche-lobe fill-out of nearly 51%. Despite its rather high temperature, 7,300 K, two magnetic spots were modeled on the primary component, a 10° radius equatorial dark spot with a T-factor of 0.88 and a 23° radius near-polar hot spot of T-factor 1.10. The component temperature difference was only ~80 K. These parameters point to a mature, early type, W UMa binary.