Messier 54 Has A Lithium Problem
Wednesday, September 10, 2014 - 18:50
in Astronomy & Space
The Milky Way galaxy is orbited by more than 150 globular star clusters - balls of hundreds of thousands of old stars dating back to the formation of the galaxy. In the constellation of Sagittarius (The Archer), the French comet hunter Charles Messier found one such cluster and it was given the designation Messier 54.For more than two hundred years after its discovery Messier 54, was thought to be similar to the other Milky Way globulars, but in 1994 astronomers determined that it was actually associated with a separate galaxy — the Sagittarius Dwarf Galaxy. It was found to be at a distance of around 90,000 light-years, more than three times as far from Earth as the galactic center. read more