Don't let the door ...

Astronomers have discovered a couple of stars being flung entirely out of the Milky Way galaxy. Apparently the only way for a star to build up the necessary velocity to escape is two start as a one-half of a binary star system plunging toward the massive back hole at the center of the galaxy. If the trajectory is just right, one star of the system will be captured by the black hole, and the other star will be left with the orbital energy of the original two-star system. In other words, it will lose one stars worth of mass and receive a velocity boost. In this case, the velocity exceeds the escape velocity of the Milky Way(about 220 km/s) and the star speeds off into intergalactic space, never to return. I hope it doesn't get lonely out there.