Berdyugina, Svetlana V.

Contact Email: Sveta.Berdyugina@oulu.fi
Institute: Astronomy Division, University of Oulu, Finland
First Coauthor: Sami K. Solanki
Institute: MPI für Aeronomie, Katlenburg-Lindau, Germany
Subject Area: Other (Please Specify Below)
Waveband: Optical
Technique: Other (Please Specify Below)
Other: Area: Solar and Stellar magnetic fields, Technique: Spectropolarimetry
Presentation: Oral Contribution: Tuesday
Title: Molecular Lines as Diagnostics of Solar and Stellar Magnetic Fields
Abstract: Thanks to recent advances in theory (Berdyugina et al. 2000, 2001) we can now calculate molecular line profiles in the presence of magnetic fields with high accuracy (Zeeman and Paschen- Back effects). The synthetic Stokes profiles of various molecular species (e.g. TiO, OH, MgH, CN, FeH) have been compared with profiles observed in sunspots. The agreement between the theory and observations is remarkable. For example, the mutually opposite polarities of different OH lines are reproduced without invoking any free parameters. Introducing molecular lines into the inversion of sunspot spectra leads to significant improvements in the deduced magnetic field vector. Here we investigate how molecular lines can be used to deduce magnetic parameters of cool stars. We find that such lines are of great interest for measuring magnetic fields on cooler stars and in starspots.