Photometric Study of the Very Short Period Shallow Contact Binary DD Comae Berenices
|Original title:||Photometric Study of the Very Short Period Shallow Contact Binary DD Comae Berenices|
|Authors:||Liying Zhu, Shengbang Qian, Zdeněk Mikulášek, Miloslav Zejda, Pavel Zvěřina, Roger Diethelm|
|Field:||Astronomy and astrophysics|
|Type:||Article in Periodical|
|Keywords:||eclipsing binaries; stellar evolution; individual star: DD Com|
The first photometric solutions of the very short period (VSP) close binary DD Comae Berenices (P=0.26920811) based on our new complete IRc light curves are derived. They show that the system belongs to shallow contact W UMa systems with an overcontact. The observed light curve distortions are explained by employing the spots model due to the latetype nature of both components. We have collected all available photometric data which we treated simultaneously using our own method based on the usage of computed model light curves as templates. We recalculated published times of light minimum and added new ones of our own to construct an OC diagram that spans over 70 years. We found that the orbital period of DD Com is continuously increasing with 0.00401 s/yr. The period increase may be caused by the mass transfer from the less massive component to the more massive one. DD Com is a rare system that lies on the expanding phase of the TRO cycle.