The fastest stars in the galaxy are galactic runaways

Scientists have discovered that the fastest stars in the Milky Way—which travel at over two million miles per hour—originally came from other galaxies, having escaped their homes after stellar explosions pushed them away at almost the speed of light.
The discovery solves a longstanding mystery about how and why these hypervelocity stars travel at such great speeds.

The fastest stars in the galaxy are galactic runaways