Photometry and Differential Corrections Analysis of Algol

Abstract

Two narrow-band light curves of Algol, at AA5500 and 4350, and one broad-band (AS 500) light curve are presented, along with their transformations to the B, V system. The comparison star, Per, is considerably closer than those used for earlier complete light curves. Two times of primary minima were determined accurately, while five others were estimated from segments of primary eclipse. Some parts of a convenient scheme for computing the reflection effect, which were omitted in an earlier paper by Wilson and Devinney, are given. Those parameters of the Wilson-Devinney model which can realistically be determined for Algol were adjusted by differential corrections simultaneously foi the three new light curves and for the 1 .6-jt infrared light curve by Chen and Reuning. for the secondary component is about 5000 K, corresponding to a spectral type of about Kl. The bolometnc albedo of the secondary component was found to be 0.52 i 0.02 p.e., in good agreement with Rucinshi's theoretical estimate of 0.4 to 0.5. However, it seems that the presently available photometry does not permit a meaningful determination of the gravity-darkening parameter for the secondary, since this component has a very small fraction of the total system luminosity.