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

TL;DR

This study analyzes CoRoT photometry of the young O-type binary HD 46149, revealing solar-like oscillations and demonstrating the potential of asteroseismology in massive stars through combined observational and modeling approaches.

Contribution

First detection of solar-like oscillations in a massive O-type star using space photometry and multi-method analysis, opening new avenues for stellar seismology in this mass regime.

Findings

Detected frequency spacings consistent with theoretical models

Confirmed pulsations are distinguishable from rotational effects

Demonstrated the feasibility of asteroseismology for massive stars

Abstract

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.