Discovery of a complex linearly polarized spectrum of Betelgeuse dominated by depolarization of the continuum

  title={Discovery of a complex linearly polarized spectrum of Betelgeuse dominated by depolarization of the continuum},
  author={Michel Auri{\`e}re and Arturo Lopez Ariste and Ph. Mathias and Agn{\`e}s L{\`e}bre and Eric Josselin and Miguel Montarg{\`e}s and P. Petit and Andrea Chiavassa and Fr{\'e}d{\'e}ric Paletou and Nicolas Fabas and Renada K. Konstantinova-Antova and Jean-François Donati and Jason H. Grunhut and Gregg A. Wade and Fabrice Herpin and Pierre Kervella and Guy Perrin and Benjamin Tessore},
  journal={Astronomy and Astrophysics},
Betelgeuse is an M supergiant that harbors spots and giant granules at its surface and presents linear polarization of its continuum. We have previously discovered linear polarization signatures associated with individual lines in the spectra of cool and evolved stars. Here, we investigate whether a similar linearly polarized spectrum exists for Betelgeuse. We used the spectropolarimeter Narval, combining multiple polarimetric sequences to obtain high signal-to-noise ratio spectra of individual… Expand

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