Magnetic activity of the spotted dwarf AP149 in the α Persei open cluster

The simultaneous photometric and spectroscopic observations of the spotted G dwarf AP149 in the young open cluster alpha Persei are analyzed here. We reconstruct the observed light curves with a two-starspot model by means of a light curve modeling technique, and find that the active regions shift oppositely along longitude on a time scale of one day. Combining with the observational data obtained by other groups, we discuss the evolution of spotted regions in the photosphere, and find that its starspots evolve not only on a short time scale but also on a long time scale. The pure chromospheric emissions for Ca IIHK and H-beta lines are derived by using the spectral subtraction technique. The variation of Ca IIHK lines' excess emission is spatially correlated to the starspot regions. There is no clear rotational modulation for the H-beta line's excess emission, probably due to the contamination of prominence emission.