When amateur astronomers turn their telescopes toward Hercules, the usual target is Messier 13, one of the brightest, easiest-to-find globular clusters in the northern sky. But a stone’s throw away is another bright companion – M92 – that runs a close second, containing some 330,000 stars orbiting the Milky Way’s core at a distance of 33,000 light years. Visible to the unaided eye under dark sky conditions, M92 was discovered by Johann Elert Bode in 1777. Four years later, Charles Messier spotted it and added the cluster to his famous catalogue. Neither man could have imagined the splendour revealed by the Hubble Space Telescope as seen in this stunning view.
Astronomers have used NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton X-ray observatory to discover an extremely luminous, variable X-ray source located outside the centre of its parent galaxy. This peculiar object could be a wandering black hole that came from a small galaxy falling into a larger one.
The drizzle of stars scattered across this image forms an irregular dwarf galaxy known as UGC 4879. Some 2.3 million light-years from its closest neighbour, UGC 4879’s isolation means that it has not interacted with any surrounding galaxies, making it an ideal laboratory for astronomers looking to understand the complex mysteries of starbirth throughout the universe.
An international research team of astronomers has, for the first time, found young populations of stars within globular clusters that have apparently developed courtesy of star-forming gas flowing in from outside of the clusters themselves. This method stands in contrast to the conventional idea of the clusters’ initial stars shedding gas as they age in order to spark future rounds of star birth.