2010/01/31 by K. Vida, K. Oláh, Zs. Kővári +8
Physics and Astronomy · #astro-ph.SR
paper · pdf · doi:10.1002/asna.200911341
published as 2010 Astronomische Nachrichten(AN), 331, 250V · 7 pages, 11 figures, 3 tables, accepted at AN, ephemeris corrected
arxiv created 2010/05/06 · arxiv updated 2013/03/08
We present more than 1000-day long photometry of EY Draconis in BV(RI)C passbands. The changes in the light curve are caused by the spottedness of the rotating surface. Modelling of the spotted surface shows that there are two large active regions present on the star on the opposite hemispheres. The evolution of the surface patterns suggests a flip-flop phenomenon. Using Fourier analysis, we detect a rotation period of Prot=0.45875d, and an activity cycle with P~350d, similar to the 11-year long cycle of the Sun. This cycle with its year-long period is the shortest one ever detected on active stars. Two bright flares are also detected and analysed.