A Hubble Space Telescope optical image of our nearest neighbor galaxy, Andromeda (M31), with an inset X-ray image of the active center made with the XMM-Newton observatory. The newly discovered ...

Our neighboring Andromeda Galaxy (Messier 31, or M31) appears to sport a lopsided arrangement of satellite galaxies that defy scientific models, stumping astronomers who are also trying to figure out ...

A massive star roughly 2.5 million light-years away in the Andromeda Galaxy has quietly disappeared, and the best explanation is that it collapsed directly into a black hole without producing a ...

What’s the farthest object you can see with only your eyes? Unless you live under extremely dark skies unspoiled by light pollution, the answer is the Andromeda Galaxy (M31), located some 2.5 million ...

Dots show locations of stars in the spectroscopic survey superimposed on an image of the Andromeda galaxy (M31). Dots are color coded according to their velocity relative to the Milky Way, as measured ...

What was the first galaxy beyond the Milky Way that you ever saw through binoculars? For me, and I suspect for many of you, the answer is the Andromeda Galaxy (M31). It’s a great choice for a few ...

The next clear evening, before the bright moon washes out the fainter stars, take a look for the Andromeda galaxy. Unless you have significant light pollution, you should be able to see it high in the ...

The 2011 Brit Marling sci-fi film Another Earth posited the idea of a mirrored version of Earth entering the Milky Way. The idea seems preposterous, and it probably is–in the film, the “other Earth” ...

Go into your backyard about 20:30 p.m. EST or thereabouts this weekend and you can see the most incredible thing – the Andromeda Galaxy – one of the farthest objects visible to the naked eye. If you ...

The typical blue spiral galaxy (top) continues to form stars actively until it collides with another galaxy. At that point, an active galactic nucleus (AGN) is formed that depletes the galaxy of dust, ...