The Andromeda nebula, M31, was a prominent example. It's visible to the naked eye from a dark ... In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the ...

Using variable stars as distance markers and the giant telescope on Mount Wilson, Edwin Hubble (then a young and little-known astronomer) was able to show that the Andromeda Nebula was over a ...

THE 200 inch telescope on Palomar Mountain has recently been used for a detailed photometric and spectroscopic study of the globular clusters associated with the Andromeda nebula. This ...

Also known as Messier 31, M31, or NGC 224, it is often referred to as the Great Andromeda Nebula in older texts. The Andromeda Galaxy is the nearest spiral galaxy to our Milky Way galaxy ...

Astronomers, maybe more than anyone, appreciate what an island of perfection our Earth is. Our orbit may put us at a perfect distance from the sun for life to flourish, but it is too small to ...

The Andromeda nebula, M31, was a prominent example ... In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the ...

Centaurus A: NGC 5128 is a galaxy in constellation Centaurus, discovered in 1826 by Scottish astronomer James Dunlop. Messier 81: NGC 3031 is a grand design spiral galaxy about 12 million light ...

Photo: Andromeda nebula plate with Hubble's handwritten circle around the variable star he discovered In 1919 American astronomer Edwin Hubble began work at the Mount Wilson Observatory in ...

Hubble had already used this knowledge in his 1924 discovery that the Andromeda nebula, containing a variable star, was more than 900,000 light years from Earth -- way beyond our own galaxy -- a ...