M-79, 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. M-79 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.
Due for launch in 2020, ESA’s Euclid satellite will set astronomers a huge challenge: to analyse 100,000 strong gravitational lenses. The gravitational deflection of light from distant astronomical sources by interposing massive galaxies can create multiple images of the source that are not just visually stunning, but are also valuable tools for probing our universe.
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.
At a ceremony held today in Germany, the European Southern Observatory and the ACe Consortium signed the largest contract ever in ground-based astronomy for key components of the 39-metre aperture European Extremely Large Telescope (E-ELT). The 85-metre-diameter, 5000 tonne dome and telescope structure will take telescope engineering into new territory.