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 HJD 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 + or - 0.002(p.e.), is in agreement with the spectroscopic mass ratio, q = 0.217 + or - 0.005(m.e.) of Hill et al. (1971) and of Tomkin and Lambert (1978). The luminosities of the third component in B and V are 0.106 + or - 0.009(p.e.) and 0.119 + or - 0.009(p.e.), respectively, where the unit is l1 + l2 + l3 = 1. The spectral type for the third component of Algol was derived as A5 V from the determined temperature T3 = 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. 34more » refs.« less