Dating our galaxy's dormant volcano

(Phys.org) —A dormant volcano—a supermassive black hole—lies at the heart of our galaxy. Fresh evidence suggests that it last erupted two million years ago.

Hubble catches cosmic snowflakes

Almost like snowflakes, the stars of the globular cluster NGC 6441 sparkle peacefully in the night sky, about 13,000 light-years from the Milky Way's galactic center. Like snowflakes, the exact number of stars in such a cluster ...