HD 197617

Period study of the contact system VW Cep New photoelectric U,B and V observations of the eclipsing contact systemVW Cep were taken in 1998-2000 and 23 new minima times were determined.The (O-C) diagram constructed using photographic and photoelectricminima times can be explained by the light-time effect caused by thepresence of a third and fourth body in the system and the long-termperiod decrease interpreted by the mass transfer from the more to theless massive component or/and the magnetic-braking process. The suddenperiod increase detected in 1999 is probably a consequence of theepisodic mass transfer from the less to the more massive component.Enhanced surface activity causes short-term apparent variations of theorbital period. The differences of times of the subsequent primary andsecondary minima show two significant periodicities P_1 = 2.94 +/- 0.07years and P_2 = 2.36 +/- 0.05 years. The latter periodicity is probablythe beat period of the orbital and rotational period at the latitudes ofmost frequent occurrence of the spots.
On the Non-Variability of BD +74 877 Not Available
On the Nonvariability of BD +74 877 Not Available
Note on the star BD+74°877 near VW Cephei Not Available
College Observatory Report. Not Available
Untersuchungen an W Ursae Majoris Sternen. I. Mit 6 Textabbildungen Not Available

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