Cool Spots on the Surface of the Active Giant PZ Mon

Abstract

Based on the multicolor (BVRIJHKL) photometric observations of the active red giant PZ Mon performed for the first time in the winter season of 2017–2018, we have determined the main characteristics of the spotted stellar surface in a parametric three-spot model. The unspotted surface temperature is T_eff = 4730 K, the temperature of the cool spots is T_s = 3500 K, their relative area is about 41%, and the temperature of the warm spots is ∼4500 K with a maximum relative area up to 20%.The distribution of spots over the stellar surface has been modeled. The warm spots have been found to be distributed at various longitudes in the hemisphere on the side of the secondary component and are most likely a result of its influence.