Cepheids are rare variable stars with periods ranging from about 1 to 120 days. Their light curve — a chart showing brightness over time — is characterized by rapid brightening followed by slow ...

A look at Edwin Hubble’s role in confirming that the Andromeda Galaxy lies beyond the Milky Way, helping expand our ...

Astronomers deployed the Hubble Space Telescope over the course of a decade to conduct 600 separate observations to produce an extraordinary mosaic of the great spiral galaxy. Astronomer John S.

For Hubble's 21st anniversary in 2011, NASA imaged Arp 273, a pair of galaxies some 300 million light-years away in the constellation Andromeda. UGC 1810 and UGC 1813 are another pair of so-called ...

On Oct. 4, 1923, Edwin Hubble took a photographic plate of the Andromeda Nebula (as it was known then) using the 100-inch Hooker telescope at Mount Wilson. The next night, Oct. 5th, he took another ...

Hubble had been in space for less than two years when its Goddard High Resolution Spectrograph detected traces of boron in a not-too-distant star. At an estimated age of 14.5 billion years, the star ...

Introduction -- Hubble's universe -- Hubble's top science accomplishments -- The message of starlight -- Crucibles of creation -- Starry tapestry -- Blaze of glory -- Hubble's invisible universe -- ...

How did a Cepheid variable star help Edwin Hubble prove the Andromeda Nebula was a galaxy? Roger Brady San Quentin, California Cepheids are rare variable stars with periods ranging from about 1 to 120 ...