In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they ...

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 ...

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 ...

Hubble’s work pushed the field of astronomy forward, starting with his paper demonstrating that some objects exist outside ...

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.

For the even larger panorama, the Panchromatic Hubble Andromeda Southern Treasury (PHAST) program was connected to it. The result is therefore called “Hubble M31 PHAT+PHAST Mosaic”, M31 being ...

What if you could find binoculars big enough to qualify as small telescopes? Get ready for the BT–127XL–SD apochromatic ...

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 ...

The Panchromatic Hubble Andromeda Southern Treasury. I. Ultraviolet and Optical Photometry of over 90 Million Stars in M31." Researchers at the University of Washington presented their findings at ...

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.

Possibly one of the best-known constellations in the northern sky, Ursa Major—or the Great Bear—contains an asterism of seven ...