Science Do black holes come in 'medium'? They do now.

Scientists report the most precise measure yet confirming the existence of an intermediate-mass black hole, which could have played a key role in the early evolution of galaxies.

By , Staff writer

Courtesy of JPL-Caltech/NASA/Reuters/File

Like shop owners tallying T-shirts, astronomers studying black holes and the roles they play in the evolution of galaxies have small, large, and extra large objects on hand. But, until now, it's been unclear that black holes come in medium sizes.