Starspot cycles of RS Canum Venaticorum type stars

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6021126

Kang, Y W

The starspot model was used to account for the photometric variations of RS Canum Venaticorum binaries. The twelve light curves of eight epochs for RS CVn, eleven light curves of six epochs for AR Lac and twelve light curves of nine epochs for V711 Tau were analyzed to investigate the cyclic variations of these systems. The spot parameters, as well as other elements of the systems, were determined for each epoch by adjusting the parameters to fit the light curves. To avoid subjective parameter adjustment, the Wilson and Devinney differential correction computer program was adopted and modified for the adjustments of the spot parameters. Models were tested using one or two circular spots on the secondary stars. The adjustable parameters are latitudes, longitudes, radii, and temperatures of the spots, the surface potentials, albedos, temperatures of the two stars and the orbital inclination. The light curve fitting was done by adjusting the spot parameters and other parameters until a good fit to the entire light curve was obtained. To find the starspot cycles, only the spot longitudinal variations were considered. For RS CVn, starspot cycles of 9.22 years and 9.00 years were determined for two spots. These cycles agree with the 9.4 year cycle of the distortion-wave found by Catalono et al.

• Research Organization: Florida Univ., Gainesville (USA)
• OSTI ID: 6021126
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
MATHEMATICAL MODELS
PARAMETRIC ANALYSIS
PHOTOMETRY
STAR MODELS
STARS
VARIATIONS