M79, a globular cluster about 41,000 light years from Earth in the constellation Lepus, is a gravitationally bound group of about 150,000 stars that was discovered in 1780 by Pierre Méchain and added to Charles Messier’s famous catalog. William Herschel, using a more powerful telescope, first called it a “globular star cluster.” Globular clusters typically orbit the core of the Milky Way and can contain more than a million stars. M79 may have a more unusual history than most given its location in the opposite direction from the core. It may be a captured cluster from a dwarf galaxy in the process of merging with the Milky Way or it may have simply formed in a region with a higher density of stars. Either way, the Hubble Space Telescope provides a stunning view.
The fuzzy collection of stars seen in this NASA/ESA Hubble Space Telescope image forms an intriguing dwarf galaxy named LEDA 677373, located about 14 million light-years away from us in the constellation Centaurus. This particular dwarf galaxy contains a plentiful reservoir of gas from which it could form stars, but it stubbornly refuses to do so. Why?
The early universe was a chaotic mess of gas and matter that only began to coalesce into distinct galaxies hundreds of millions of years after the Big Bang. It would take several billion more years for such galaxies to assemble into massive galaxy clusters — or so scientists had thought. Now astronomers have detected a massive, sprawling, churning galaxy cluster that formed only 3.8 billion years after the Big Bang, some 10 billion light years from Earth.