2002A&A...381..517A

In this work, spot parameters are determined for two stars, namely, AG Dor and HU Vir, from their photometric variability and λ7055Å TiO band depth. Applying the photometric modelling code spotpic, we have found two modulating spots together with a non-modulating component on the photosphere of AG Dor in December 96/January 97. The spot temperatures are constrained to be between 4300K and 4600K for the modulating component, and cooler, viz., 4000K, for the non-modulating one. Therefore, the non-modulating component of the spot distribution on AG Dor at this epoch is held to be totally responsible for the presence of the TiO band in the spectra of this K1 dwarf with photospheric temperature of 5000K. AG Dor's total coverage of spots is determined to be between 4% and 7% for the modulating component and 26.5% for the non-modulating one. For HU Vir, the light and colour curves were modelled with two spots with temperatures of 4450 and 4050K. In this case we did not include the non-modulating component in the model.