BVR_cI_c CCD Observations and Analyses of the 0.9-day Period, Totally Eclipsing, Solar Type Binary, NS Camelopardalis

摘要

CCD, BVR_c I_c light curves of NS Cam were taken on 2020 January 01, 20, 21, 22, 23, February 04, 22, 23, March 01, and April 07 at the Dark Sky Observatory, North Carolina, with the 0.81-m reflector of Appalachian State University by Daniel Caton, Danny Faulkner, and Ronald Samec. Five times of minimum light were determined from our present observations, which include three primary eclipse and two secondary eclipses. We selected four times of low light from parabola fits of ASAS-SN observations. The results include a newly determined quadratic ephemeris. Thus, from our 20.3-year study, the period is found to be decreasing. Since the estimated temperatures are ~ 6250± 500 K for the primary component and ~ 5690 K for the secondary component, this is probably due to magnetic braking. A Wilson-Devinney analysis reveals that the system is a W UMa shallow contact binary. The component temperature difference is ~ 560 K. The mass ratio is also somewhat extreme, M_2 / M_1 = 0.2 130 ±0.0001. The total eclipses make this a firm determination. Its Roche Lobe fill-out is 17%. The cool spot was at midlatitude (co-latititude = 45°), but overlaps the pole with a large radius of~ 60° and a T-factor of~ 0.68. The binary inclination is high, 85.0, resulting in total eclipses. As a result, the primary minimum has a time of constant light with an eclipse duration of 104 minutes.