Chromospheric Activity in K Stars

M. VIEYTES; P. MAUAS; C. CINCUNEGUI; R. DÍAZ

Coimbra, Portugal

Conferencia; The Physics of Chromospheric Plasmas; 2007

We computed chromospheric models for six stars of spectral type K, in most cases in two different moments of activity. The stars were chosen with 0.82 <B-V< 0.90 including the widely studied star arepsilon Eridani. The stars in the sample have a wide variety of magnetic activity levels, which allows us to study the differences in structures induced by stellar activity, and expand our previous work for G stars including the Sun as a star. The models were constructed to obtain the best possible match with the Ca II K and Hβ observed profiles. We also computed the net radiative losses for each model to constrain the heating mechanism to maintain the structure in the atmosphere predicted by the models. We find a strong correlation between these losses and SCa II, the index generally used as a proxy for activity, as we found for G stars.