A new, distant arm of the Milky Way galaxy

(PhysOrg.com) -- Our Milky Way galaxy, like other spiral galaxies, has a disk with sweeping arms of stars, gas, and dust that curve around the galaxy like the arms of a huge pinwheel.

Close-knit pairs of supermassive black holes discovered in merging galaxies

Astronomers have discovered 16 close-knit pairs of supermassive black holes in merging galaxies. These black-hole pairs, also called binaries, are about a hundred to a thousand times closer together than most that have been observed before, providing astronomers a glimpse into how these behemoths and their host galaxies merge -- a crucial part of understanding the evolution of the universe.

Dark-matter galaxy detected: hidden dwarf lurks nearby?

Galaxy X: An entire galaxy—made mainly of dark matter—may be lurking just outside our own, scientists say.

NASA's Fermi telescope finds giant structure in our galaxy

NASA's Fermi Gamma-ray Space Telescope unveiled a previously unseen structure centered on the Milky Way. The feature spans 50,000 light-years.