BV light curve analysis of Algol

Abstract

The photoelectric light curves of Algol were made with a total of 1034 observations in B and V at Yonsei University Observatory. The two times of minimum light determined are HID 2,445,263.0296 and HJD 2,445,739.0030. The light curves were analyzed using the Wilson-Devinney method. It was reconfirmed that the secondary component of Algol is filling its Roche lobe. The adjusted photometric mass ratio, q = 0.227 ± 0.002(p.e.), is in agreement with the spectroscopic mass ratio, g = 0.217 ± 0.005(m.e.) of Hill and coworkers and of Tomkin and Lambert. The luminosities of the third component in B and V are 0.106 ± 0.009(p.e.) and 0.119 ± 0.009(p.e.), respectively, where the unit is /i + / 2 + ¿3 = 1-The spectral type for the third component of Algol was derived as A5 V from the determined temperature T 3 = 8500 K and color index B-V= +0.13. The radius of this star has been derived from the ratio of radii and the absolute dimensions of the primary. The radius and mass relation suggest that this component is a main-sequence star. Some evolutionary aspects of Algol have been suggested.