Detection of frequency spacings in the young O-type binary HD 46149
from CoRoT photometry

P. Degroote$^1$
M. Briquet$^1$
M. Auvergne$^2$
S. Sim'on-D'iaz$^{3,4}$
C. Aerts$^{1,5}$
A. Noels$^6$
M. Rainer$^7$
M. Hareter$^8$
E. Poretti$^7$
L. Mahy$^6$
R. Oreiro$^1$
M. Vu{v c}kovi{'c}$^1$
K. Smolders$^1$
A. Baglin$^2$
F. Baudin$^9$
C. Catala$^2$
E. Michel$^2$
R. Samadi$^2$

1 - Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200D, B-3001
Leuven, Belgium
2 - LESIA, Observatoire de Paris, CNRS UMR 8109, Universit'e Pierre et Marie Curie, Universit'e Denis Diderot, 5 place J. Janssen, 92105 Meudon, France
3 - Instituto de Astrof'isica de Canarias, 38200 La Laguna, Tenerife, Spain.
and Departamento de Astrof'isica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain.
4 - Department of Astrophysics, IMAPP, University of Nijmegen, PO Box 9010,
6500 GL Nijmegen, The Netherlands
5 - Institut d'Astrophysique et de G'eophysique Universit'e de Li`{e}ge,
All'{e}e du 6 Ao^{u}t 17, B-4000 Li`{e}ge, Belgium
6 - INAF -- Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (LC), Italy
7 - Institut f"ur Astronomie, Universit"at Wien T"urkenschanzstrasse 17, A-1180
Vienna, Austria
8 - Institut d'Astrophysique Spatiale, CNRS/Universit'e Paris XI UMR 8617, F-091405 Orsay, France

Using the CoRoT space based photometry of the O-type binary HD46149, stellar atmospheric effects related to rotation can be separated from pulsations, because they leave distinct signatures in the light curve. This offers the possibility of characterising and exploiting any pulsations seismologically.

Combining high-quality space based photometry, multi-wavelength photometry, spectroscopy and constraints imposed by binarity and cluster membership, the detected pulsations in HD46149 are analyzed and compared with those for a grid of stellar evolutionary models in a proof-of-concept approach.

We present evidence of solar-like oscillations in a massive O-type star, and show that the observed frequency range and spacings are compatible with theoretical
predictions. Thus, we unlock and confirm the strong potential of this seismically unexplored region in the HR diagram.

Reference: A&A, in press
Status: Manuscript has been accepted