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An observational study of selected zero-age and evolved contact binary systems
Abstract
We investigate four eclipsing binary systems V508 Cyg, V719 Her, DN Aur and KN Per, selected from Behlen observatory variable star survey. The 0.76 m automated telescope CCD photometer and associated computer facility provides the photometric data for the V and R bandpass light curves. The spectral class of all the systems (except KN Per which is published) come from color. Photometric solutions are computed with the help of the latest 1993 version of the Wilson-Devinney model. The solutions show that the four systems are in contact configuration. The Period-Spectral type diagram shows their evolutionary status as zero-age and evolved contact systems. V508 Cyg: The analysis of 700 data points gives a period of 0.779659 days. The analysis shows two solutions with mass ratio ($q=m\sb2/m\sb1$) of 0.44 and 1.19 that give an A-type (primary eclipse occurs at transit) and W-type (primary eclipse occurs at occultation) W UMa configuration respectively. Our analysis suggests that V508 Cyg may probably be an evolve contact system showing case B (shell H-burning) mass loss. V719 Her: The period from 347 data points is 0.400983 days. The period of this system appears to decrease at a rate of about 0.5 sec/yr. The photometric solution shows a mass ratio of 0.29 and A-type W UMa configuration. V719 Her probably is in zero-age state. DN Aur: Period from 647 data points is 0.616889 days. Two photometric solutions with third light are presented, one with spot and the other without. Both show a mass ratio around 0.21 with A-type W UMa configuration. DN Aur could be an evolved contact showing case A (core H-burning) mass loss. KN Per: The period of the system from 669 data points is 0.866460 days. Two solutions with mass ratio around 0.25 are presented. One suggest a dark spot on the secondary. The configuration is A-type W UMa system. This star possibly is another example of evolved case B mass loss.
Subject Area
Astronomy|Astrophysics
Recommended Citation
Goderya, Shaukat Naaman, "An observational study of selected zero-age and evolved contact binary systems" (1995). ETD collection for University of Nebraska-Lincoln. AAI9604413.
https://digitalcommons.unl.edu/dissertations/AAI9604413