On the Distortion Wave in the Short Period RS CVn Type Eclipsing Binary WY Cancri

Abstract

The eclipsing binary WY Cancri (G5 V, M2 V), having a period of O^ḍ 82937122, has been classified as a short period RS CVn type binary (Hall, 1976). Chambliss (1965), Oliver (1974), Sarma (1976), Awadulla and Budding (1979) have reported observations of this system. In order to determine a more reliable period of the distortion wave, its source, nature and period of the overall luminosity change from one observing season to the next, we have included this star in the observing schedule of RS CVn binaries at our observatory. Observations were made in standard UBV filters using the 48-inch reflector telescope of the Japal-Rangapur Observatory. The stars BD+28° 1672 and BD+27° 1701 were used as a comparison and check stars respectively. The light curves in yellow and blue colours for 1973, ‘76, ‘77 and ‘78 are shown in figure 1 which shows the following features:

• (i) Changes in overall luminosity outside the eclipses from one observing season to the next.

• (ii) Presence of the distortion wave outside the eclipses.

• (iii) Variation in the depth of the primary minimum which is not very prominent compared to the secondary.