A Photometric Study of the Total Eclipsing Algol Binary KK Draconis

Volume 52 number 2 (2024)

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Edward J. Michaels

Waffelow Creek Observatory, 10780 FM 1878, Nacogdoches, TX 75961; astroed@ejmj.net

Abstract

Multi-band light curves of the eclipsing binary star KK Draconis are presented. The primary eclipse is total with a depth of 3.1 magnitudes in the Johnson B passband. A simultaneous five-color light curve solution was obtained using the Wilson-Devinney program. The solution results describe a semidetached configuration with a mass ratio of M2 / M1 = 0.50, an orbital inclination of i = 88.4°, and a temperature difference of ΔT = 2074 K between the component stars. Asymmetries in the light curves were modeled with cool spots located on the K7 secondary star. New linear and quadratic ephemerides were computed, giving an orbital period of 1.192834 d which is decreasing at a rate of –3.941 × 10^–7 d yr^–1.