The result is an impressive panorama, revealing approximately 200 million stars and extending six times the apparent diameter of the full Moon in the night sky.

Astronomers refer to the Andromeda Galaxy as M31 because it is the 31st object listed in the Messier Catalog, a list of astronomical objects compiled by French astronomer Charles Messier.

Also called M31—and our closest giant neighboring galaxy at just 2.5 million light years away—Andromeda is home to at least a trillion stars. Like the Milky Way, it’s a spiral galaxy ...

called the Andromeda Nebula (after the constellation in which it was located). It was entry 31 in Charles Messier's 18th century catalog of interesting fuzzy objects, and is thus also called M31 ...

The Panchromatic Hubble Andromeda Southern Treasury. I. Ultraviolet and Optical Photometry of over 90 Million Stars in M31, The Astrophysical Journal (2025). DOI: 10.3847/1538-4357/ad7e2b ...

Also known as M31, Andromeda is the Milky Way’s closest major galaxy, measuring roughly 152,000 light years across, with almost the same mass as our home galaxy. The younger James Webb Space ...

The Hubble Space Telescope has provided the most detailed survey of the Andromeda galaxy, revealing new clues about its ...

Before then, the orthodox cosmological view was that the Milky Way encompassed the entire known universe, and that Andromeda had to be part of it as a result. Hubble's estimate that M31 was 2.5 ...

Under the right conditions, you can even see Andromeda (also known as M31) with the naked eye. In addition, it may be home to upward of 1 trillion stars, many of which are close to the telescope's ...

It is a panoramic view of the neighboring Andromeda galaxy, located 2.5 million light-years away. It took over 10 years to make this vast and colorful portrait of the galaxy, requiring over 600 ...