On the origin of the hypervelocity runaway star HD271791

TL;DR

This paper investigates the origin of the hypervelocity star HD271791, concluding it was likely ejected through dynamical interactions in a dense star cluster rather than a supernova explosion.

Contribution

It proposes a new explanation for the star's high velocity, emphasizing dynamical encounters over binary-supernova scenarios.

Findings

HD271791's velocity cannot be explained by binary-supernova ejection.

Dynamical interactions in dense star clusters are a plausible origin.

Exchange encounters with very massive stars can produce hypervelocity stars.

Abstract

We discuss the origin of the runaway early B-type star HD271791 and show that its extremely high velocity (\simeq 530-920 km/s) cannot be explained within the framework of the binary-supernova ejection scenario. Instead, we suggest that HD271791 attained its peculiar velocity in the course of a strong dynamical encounter between two hard massive binaries or via an exchange encounter between a hard massive binary and a very massive star, formed through runaway mergers of ordinary massive stars in the dense core of a young massive star cluster.