The First Precision Photometric Observations and Analyses of the Totally Eclipsing, Solar Type Binary, V1302 Herculis

Volume 51 number 1 (2023)

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Ronald G. Samec

Pisgah Astronomical Research Institute, 318 Monti Drive, Anderson, SC 29625; ronaldsamec@gmail.com

Daniel Caton

Dark Sky Observatory, Department of Physics and Astronomy, Appalachian State University, 525 Rivers Street, Boone, NC 28608-2106; catondb@appstate.edu

Danny Faulkner

Johnson Observatory, 1414 Bur Oak Court, Hebron, KY 41048; dfaulkner@answersingenesis.org

Abstract

CCD, BVRI light curves of the W UMa variable V1302 Her were taken on 24, May, 07, and 23. 24, 27 June 2020 at the Dark Sky Observatory, North Carolina, USA, with the 0.81-m reflector of Appalachian State University. From our present observations, which include three primary eclipses and three secondary eclipses, we determined a linear and a quadratic ephemeris: JD Hel MinI = 2459027.6675±0.0033 + 0.3162911±0.0000003 × E JD Hel MinI = 2459027.6764±0.0033d + 0.31629542±0.00000087 × E + 0.00000000027±0.00000000005 × E2 From our 16-year period study, the period is found to be increasing. This could be due to mass transfer making the mass ratio decrease (q = M2 / M1; all pairs of values should be corrected with a phase shift of 0.5). A Wilson-Devinney analysis reveals that the system is an A-type (more massive component is the hottest) overcontact W UMa binary with a fairly extreme mass ratio (q = 0.2426 ± 0.0003, 1 / q = M1 / M2 = 4.1). Its Roche Lobe fill-out is ~23%. One hot spot was needed in the solution. The temperature difference of the components is only ~263 K, with the more massive component as the slightly hotter one, so that in the present observations, it is an A-type W UMa binary. The inclination is high, 87.0 ± 0.2, resulting in a total primary eclipse.