For nearly a century, astronomers have known that the universe is expanding. Most galaxies are carried outward with the flow ...

A vast, flat sheet of dark matter may solve the long-standing mystery of why our neighboring galaxy Andromeda is speeding ...

On a clear night, the Milky Way and the Andromeda galaxy look like close neighbors. In space, they really are.

A massive star in the nearby Andromeda galaxy has simply disappeared. Some astronomers believe that it's collapsed in on ...

In 2014, a NASA telescope observed that the infrared light emitted by a massive star in the Andromeda galaxy gradually grew brighter. The star glowed more intensely with infrared light for around ...

A flat plane of dark matter beyond the Local Group may explain why nearby galaxies move away from us instead of falling ...

Astronomers tracked a star in Andromeda as it dimmed and vanished without the usual fiery explosion, offering rare clues to ...

You might think galaxies can’t ever find each other in our runaway cosmos, but it turns out gravity can sometimes overcome ...

A “disappearing” star in the Andromeda galaxy is the closest and best candidate for a newborn black hole that astronomers have ever seen ...

A new composite image of the Andromeda Galaxy is offering an unprecedented view of our closest spiral galactic neighbor. Composed by NASA and international space partners, the image combines data from ...

Andromeda is also a flattened spiral like the Milky Way, but it's twice as large — 220,000 light-years across versus 105,000 for the Milky Way — and crammed with a trillion suns. Can you even begin to ...

A new composite image of the Andromeda Galaxy is offering an unprecedented view of our closest spiral galactic neighbor. Composed by NASA and international space partners, the image combines data from ...