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First polarimetric measurements and modeling of the Paschen-Back effect in CaH transitions

S. V. Berdyugina·D. M. Fluri·R. Ramelli·M. Bianda·D. Gisler·J. O. Stenflo
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Abstract

We report the first spectropolarimetric observations and modeling of CaH transitions in sunspots. We have detected strong polarization signals in many CaH lines from the A-X system, and we provide the first successful fit to the observed Stokes profiles using the previously developed theory of the Paschen-Back effect in arbitrary electronic states of diatomic molecules and polarized radiative transfer in molecular lines in stellar atmospheres. We analyze the CaH Stokes profiles together with quasi-simultaneous observations in TiO bands and conclude that CaH provides a valuable diagnostic of magnetic fields in sunspots, starspots, cool stars, and brown dwarfs.

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S. V. Berdyugina, D. M. Fluri, R. Ramelli, M. Bianda, D. Gisler, J. O. Stenflo. 2006-10-19. First polarimetric measurements and modeling of the Paschen-Back effect in CaH transitions. https://doi.org/10.1086/508159

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