Dennis Overbye in the New York Times:
Was it something we said?
A star has been spotted flying out of the Milky Way. And it apparently won’t be back.
Astronomers from the Harvard-Smithsonian Center for Astrophysics recently clocked the star’s velocity at 1.5 million miles an hour, twice as much as it needs to escape the galaxy’s gravitational field, making this the first galactic runaway to be discovered.
The runaway is a blue star about three times as massive as the Sun in the constellation Hydra. It is known formally and numbingly as SDSS J090745.0+24507, based on its coordinates in the sky, but Dr. Warren Brown of the center, the leader of the team that discovered it, also refers to it simply as “the outcast.”
More here.