Long-term spectropolarimetric monitoring of the cool supergiant betelgeuse

I. Bedecarrax; P. Petit; M. Aurière; J. Grunhut; G. Wade; A. Chiavassa; J.-F. Donati; R. Konstantinova-Antova; G. Perrin

doi:10.1051/eas/1360018

All issues

Volume 60 (2013)

EAS Publications Series, 60 (2013) 161-165

Abstract

Issue		EAS Publications Series Volume 60, 2013 Betelgeuse Workshop 2012 The Physics of Red Supergiants: Recent Advances and Open Questions


Page(s)		161 - 165
Section		Atmospheric Structure and Dynamics
DOI		https://doi.org/10.1051/eas/1360018
Published online		23 May 2013

Betelgeuse Workshop 2012
P. Kervella, T. Le Bertre and G. Perrin (eds)
EAS Publications Series, 60 (2013) 161-165

Long-term spectropolarimetric monitoring of the cool supergiant betelgeuse

I. Bedecarrax¹, P. Petit¹, M. Aurière¹, J. Grunhut², G. Wade³, A. Chiavassa⁴, J.-F. Donati¹, R. Konstantinova-Antova⁵ and G. Perrin⁶

¹ IRAP, Université de Toulouse, CNRS, Toulouse, France
² ESO, Garching bei München, Germany
³ Department of Physics, Royal Military College of Canada, Kingston, Ontario, Canada
⁴ Laboratoire Lagrange, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d’Azur, Nice, France
⁵ Institute of Astronomy and NAO, Bulgarian Academy of Sciences, Sofia, Bulgaria
⁶ Observatoire de Paris, LESIA, Meudon, France

Abstract

We report on a long-term monitoring of the cool supergiant Betelgeuse, using the NARVAL and ESPaDOnS high-resolution spectropolarimeters, respectively installed at Telescope Bernard Lyot (Pic du Midi Observatory, France) and at the Canada-France-Hawaii Telescope (Mauna Kea Observatory, Hawaii). The data set, constituted of circularly polarized (Stokes V) and intensity (Stokes I) spectra, was collected between 2010 and 2012. We investigate here the temporal evolution of magnetic field, convection and temperature at photospheric level, using simultaneous measurements of the longitudinal magnetic field component, the core emission of the Ca II infrared triplet, the line-depth ratio of selected photospheric lines and the radial velocity of the star.