  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.
