Binary interaction dominates the evolution of massive stars

Understand

The presence of a nearby companion alters the evolution of massive stars in binary systems, leading to phenomena such as stellar mergers, X-ray binaries and gamma-ray bursts.

• Unambiguous constraints on the fraction of massive stars affected by binary interaction were lacking.
• We simultaneously measured all relevant binary characteristics in a sample of Galactic massive O stars and quantified the frequency and nature of binary interactions.
• Over seventy per cent of all massive stars will exchange mass with a companion, leading to a binary merger in one third of the cases.