Exploring the Properties of Mira-Type Stars with Spectropolarimetry
نویسنده
چکیده
Mira-type stars are luminous red giants that have pulsation periods that last anywhere between 100 and 700 days. The irregular behavior of their periods and atmospheric properties flag them as excellent candidates for astrophysical studies of non-spherical stars. This paper focuses on the linear polarization of light emitted from three Mira-type stars: Mira itself, R Leo, and V CVn. Polarimetric data from the University of Wisconsin's Half-Wave Spectropolarimeter (HPOL) database, as well as other archives of polarimetric data, provide us with insight into the atmospheric and geometrical properties of these three stars. We were able to study the net polarizations and position angles alongside light curves provided by AAVSO. The observed variable polarization is a clear signature of evolving aspherical geometries for these stars. However, we found a major surprise concerning the polarimetric characteristics in V CVn, which suggest that V CVn is unlike a traditional Mira-type variable star. We end with an exploration of new possibilities regarding the atmospheric properties of V CVn.
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