Mystery of the speeding star: Evidence of a violent stellar merger in Taurus

Star system: HP Tauri | Distance from the Sun: 559 light years

Astronomers have discovered that the unusual star HP Tau/G2 is likely the result of two stars crashing into each other. This 'walkaway' star is currently speeding away from its birthplace alongside another star, KPNO 15, after a complex gravitational dance in a multiple star system caused them to be ejected 5,600 years ago. HP Tau/G2 exhibits strange characteristics for its age, including an oddly large size, fast rotation, and a flattened shape. 

The study suggests that after the ejection, the internal components of G2 became unstable and merged in a massive outburst about 2,000 years ago. This discovery indicates that such stellar mergers might be a common way for young stars to evolve and could explain other mysterious brightenings observed in our galaxy.

Scientific study

The Walkaway Star HP Tau/G2: Evidence for a Stellar Merger (external link)