M61, one of the largest members of the Virgo cluster of galaxies, is well positioned for amateurs in the evening sky, a face-on spiral that features a hidden, 5-million solar-mass black hole in its luminous core. It was first observed in 1779 and remains a popular target for Earth- and space-based telescopes. This spectacular image combines data from the Hubble Space Telescope and the FORS camera on the European Southern Observatory’s Very Large Telescope, revealing an unprecedented wealth of detail. Located more than 52 million light years from Earth, M61 is formally classified as an intermediate barred spiral. It’s also a prodigious starburst galaxy with brilliant ruby-red patches of recent star formation. Remarkably, eight supernovae have been spotted in M61 since the first was noted in 1926.
A matter of scientific speculation since the 1930s, dark matter itself cannot yet be detected, but its gravitational effects can be. Now, eight scientists from Johns Hopkins University consider the possibility that the first black hole binary detected by LIGO could be part of this mysterious substance known to make up about 85 percent of the mass of the universe.
Globular clusters offer some of the most spectacular sights in the night sky. These ornate spheres contain hundreds of thousands of stars, and reside in the outskirts of galaxies. The Milky Way contains over 150 such clusters — and the example shown in this NASA/ESA Hubble Space Telescope image, named NGC 362, is one of the most unusual ones.