When Size Matters
“Stars in a distant galaxy move at stunning speeds — greater than 1 million mph, astronomers have revealed.
These hyperactive stars move at about twice the speed of our sun through the Milky Way, because their host galaxy is very massive, yet strangely compact. The scene, which has theorists baffled, is 11 billion light-years away. It is the first time motions of individual stars have been measured in a galaxy so distant.
While the stars’ swiftness is notable, stars in other galaxies have been observed to travel at similarly high speeds. In those situations, it was usually because they were interlopers from outside, or circling close to a black hole.
But in this case, the stars’ high velocities help astronomers confirm that the galaxy they belong to really is as massive as earlier data suggested.”