ZHU, Liying, Shengbang QIAN, Zdeněk MIKULÁŠEK, Miloslav ZEJDA,
Pavel ZVĚŘINA a Roger DIETHELM. Photometric Study of the Very
Short Period Shallow Contact Binary DD Comae Berenices.
Astronomical Journal, Springer Science+Business Media, 2010,
roč. 140, č. 1, s. 215-223. ISSN 0004-6256.
Astronomie a nebeská mechanika, astrofyzika
Článek v odborném periodiku
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.