Non-radial oscillations in the red giant HR 7349 measured by CoRoT^*

¹ Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium e-mail: fabien@ster.kuleuven.be
² Institut d'Astrophysique Spatiale, Campus d'Orsay, 91405 Orsay, France
³ LESIA, UMR8109, Université Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, 92195 Meudon, France
⁴ Thüringer Landessternwarte, 07778 Tautenburg, Germany
⁵ University of Birmingham, School of Physics and Astronomy, Edgbaston, Birmingham B15 2TT, UK
⁶ Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels, Belgium
⁷ Institute for Astronomy, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
⁸ Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
⁹ Institut d'Astrophysique et de Géophysique de l'Université de Liège, Allée du 6 Août 17, 4000 Liège, Belgium

Received: 23 June 2009
Accepted: 7 October 2009

Abstract

Context. Convection in red giant stars excites resonant acoustic waves whose frequencies depend on the sound speed inside the star, which in turn depends on the properties of the stellar interior. Therefore, asteroseismology is the most robust available method for probing the internal structure of red giant stars.

Aims. Solar-like oscillations in the red giant HR 7349 are investigated.

Methods. Our study is based on a time series of 380 760 photometric measurements spread over 5 months obtained with the CoRoT satellite. Mode parameters were estimated using maximum likelihood estimation of the power spectrum.

Results. The power spectrum of the high-precision time series clearly exhibits several identifiable peaks between 19 and 40 μHz showing regularity with a mean large and small spacing of  = 3.47 ± 0.12 μHz and  = 0.65 ± 0.10 μHz. Nineteen individual modes are identified with amplitudes in the range from 35 to 115 ppm. The mode damping time is estimated to be 14.7 days.