Issue |
EAS Publications Series
Volume 71-72, 2015
The Physics of Evolved Stars: A Conference Dedicated to the Memory of Olivier Chesneau
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Page(s) | 71 - 74 | |
Section | Winds, Mass Loss, Jets | |
DOI | https://doi.org/10.1051/eas/1571013 | |
Published online | 01 December 2015 |
E. Lagadec, F. Millour and T. Lanz (eds)
EAS Publications Series, 71–72 (2015) 71-74
Hydrogen Lines in Mira Stars Through Interferometry and Polarimetry
1 Kiepenheuer Institut für Sonnenphysik, Freiburg, Germany
2 Laboratoire Lagrange, UMR 7293, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d'Azur, BP. 4229, 06304 Nice Cedex 4, France
3 ESO, Karl-Schwarzschild-St. 2, 85748 Garching bei München, Germany
Balmer lines in emission are the most prominent features in Mira stars spectra and have a strong potential as a proxy to study the lower atmosphere's dynamics. In Fabas et al. ([1]), we accumulated spectropolarimetric observations of Balmer lines in emission. As the shock is propagating outwards, linear polarization rate increases and the angle of this polarization evolves. Assuming that linear polarization arises from anisotropic scattering, it has the potential of telling us about the geometric structure of the shock as it propagates and the study of such atmospheric structures can typically be performed with interferometry. In 2012, AMBER data on the Mira star omicron Ceti were collected in which the Brackett γ line is studied. The data show signatures in the interferometric observables around this line. Olivier Chesneau was in the jury evaluating the PhD thesis of N. Fabas and he was seduced by the idea to study these shock waves with interferometry and use polarimetry as a complementary study.
© EAS, EDP Sciences, 2015