Largest Galaxy Discovered

A concentration of stars that stretches for 6 million light years--more than 60 times the size of the Milky Way--is the largest galaxy ever discovered, astronomers say in the journal Science. The study, published last week, said the central galaxy in a distant cluster of galaxies called Abell 2029 has more than 100 trillion stars. The Milky Way, which includes the sun and its solar system, has about 3 billion stars.

Jeffrey R. Kuhn, a Michigan State University astronomer who co-authored the study, said the Abell 2029 central galaxy “is the largest single galaxy that has been resolved.”

“If we talk about the galaxy and the halo (diffused light around the galaxy) as a single entity, then it is the largest object that we are aware of,” he said.

Kuhn and his co-investigators, Juan M. Uson of the National Radio Astronomy Observatory and Stephen P. Boughn of Haverford College, determined the size of the galaxy using a series of observations from the Kitt Peak National Observatory in Arizona.