The B0.5IVe CoRoT target HD 49330. I. Photometric analysis from CoRoT data

Anne-Laure Huat (1, 2) , Anne-Marie Hubert (1, 2) , Frederic Baudin (3) , Michèle Floquet (1, 2) , Coralie Neiner (1, 2) , Yves Frémat (4, 1, 2) , Juan Gutiérrez (1, 2) , L. Andrade (5) , Bertrand de Batz (1, 2) , Pascual Diago (6) , Marcelo Emilio (7) , Francisco Espinosa (1, 2) , Juan Fabregat (6) , Eduardo Janot-Pacheco (5) , A. Leroy (8) , Christophe Martayan (4, 1, 2) , Thierry Semaan (1, 2) , Julia Suso (6) , Michel Auvergne (8) , Claude Catala (8) , Eric Michel (8) , Davoud-Reza Samadi (8)

1 GEPI - Galaxies, Etoiles, Physique, Instrumentation
2 Physique stellaire et galactique
3 IAS - Institut d'astrophysique spatiale
4 ROB - Royal Observatory of Belgium = Observatoire Royal de Belgique
5 Universidade de São Paulo
6 UV - Universitat de València
7 Obervatório Astronômico, Universidade Estadual de Ponta Grossa
8 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique

Context: Be stars undergo outbursts producing a circumstellar disk from the ejected material. The beating of non-radial pulsations has been put forward as a possible mechanism of ejection.
Aims: We analyze the pulsational behavior of the early B0.5IVe star HD 49330 observed during the first CoRoT long run towards the Galactical anticenter (LRA1). This Be star is located close to the lower edge of the beta Cephei instability strip in the HR diagram and showed a 0.03 mag outburst during the CoRoT observations. It is thus an ideal case for testing the aforementioned hypothesis.
Methods: We analyze the CoRoT light curve of HD 49330 using Fourier methods and non-linear least square fitting.
Results: In this star, we find pulsation modes typical of beta Cep stars (p modes) and SPB stars (g modes) with amplitude variations along the run directly correlated with the outburst. These results provide new clues about the origin of the Be phenomenon as well as strong constraints on the seismic modelling of Be stars.

Domaines: Astrophysique [astro-ph]; Planète et Univers [physics]

Anne-Laure Huat, Anne-Marie Hubert, Frederic Baudin, Michèle Floquet, Coralie Neiner, et al.. The B0.5IVe CoRoT target HD 49330. I. Photometric analysis from CoRoT data. Astronomy and Astrophysics - A&A, 2009, 506, pp.95-101. ⟨10.1051/0004-6361/200911928⟩. ⟨hal-03785200⟩