Abstract:

Time-series CCD photometry of the contact system V839 Oph on May, June and July 2004 showed a continuous brightening of the system in all phases of the light curve. A possible explanation of this brightening could be enhanced (magnetic) activity of the system, also noticed in the past. Mass transfer and/or energy exchange between the two components can explain the observed increase of brightness. All possible cases, concerning the location and shape of the spotted area, are discussed and the most probable model is presented.

Website