The Milky Way can’t hold onto all of its stars. Some of them get ejected into intergalactic space and spend their lives on an uncertain journey. A team of astronomers took a closer look at the most massive of these runaway stars to see what they could find out how they get ejected.
When astronomers observe a field of stars in the Milky Way, one of the things they measure is the velocity distribution. The overall velocity distribution of the stellar population reflects the rotation of the galaxy. And when a star isn’t harmonized with the galaxy’s rotation, it catches astronomers’ attention.
That’s somewhat similar to a plot point in the third Hitchhiker’s Guide to the Galaxy book, except that it’s because a planet is inside a huge dense cloud and can’t see the rest of the universe.