First Precision Photometric Observations and Analyses of the Totally Eclipsing, Solar Type Binary V573 Pegasi
Volume 46 number 1 (2018)
- Ronald G. Samec
- Faculty Research Associate, Pisgah Astronomical Research Institute, 1 PARI Drive, Rosman, NC 28772; ronaldsamec@gmail.com
- Daniel B. Caton
- Dark Sky Observatory, Department of Physics and Astronomy, Appalachian State University, 525 Rivers Street, Boone, NC 28608
- Danny R. Faulkner
- Johnson Observatory, 1414 Bur Oak Court, Hebron, KY 41048
Abstract
CCD VRcIc light curves of V573 Peg were taken 26 and 27 September and 2, 4, and 6 October, 2017, at the Dark Sky Observatory in North Carolina with the 0.81-m reflector of Appalachian State University. Five times of minimum light were calculated, two primary and three secondary eclipses, from our present observations. The following quadratic ephemeris was determined from all available times of minimum light: JD Hel MinI = 2456876.4958 (2) d + 0.41744860 (8) × E –2.74 (12) × 10–10 × E2, where the parentheses hold the ± error in the last two digits of the preceding value. A 14-year period study (covered by 24 times of minimum light) reveals a decreasing orbital period with high confidence, possibly due to magnetic braking. The mass ratio is found to be somewhat extreme, M2 / M1 = 0.2629 ± 0.0006 (M1 / M2 = 3.8). Its Roche Lobe fill-out is ~25%. The solution had no need of spots. The component temperature difference is about 130 K, with the less massive component as the hotter one, so it is a W-type W UMa Binary. The inclination is 80.4 ± 0.1°. Our secondary eclipse shows a time of constant light with an eclipse duration of 24 minutes. More information is given in the following report.