On 14 September 2015, the Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves from the merger of two black holes 29 and 36 times the mass of the Sun. New research suggests that the two black holes might have resided inside a single, massive star whose death generated a gamma-ray burst detected by the Fermi Space Telescope.
Researchers from the University of Cambridge and Queen Mary University of London have shown how a bizarrely shaped black hole could cause Einstein’s general theory of relativity, a foundation of modern physics, to break down. However, such an object could only exist in a universe with five or more dimensions.
In May 2010, a South African amateur astronomer pointed his telescope toward nearby galaxy NGC 300 and discovered what appeared to be a supernova — a massive star ending its life in a blaze of glory. However, SN 2010da is what we call a ‘supernova impostor’ — something initially thought to be a supernova, but later releaved as a massive star showing an enormous flare of activity.
It has been suggested that gamma rays coming from the dense region of space in the inner Milky Way galaxy could be caused when invisible dark matter particles collide, but two new studies suggest that the gamma ray bursts are due to other astrophysical phenomena such as fast-rotating stars called millisecond pulsars.
Astronomers can’t find any sign of the black hole at the centre of the quasar SDSS J1011+5442, and they couldn’t be happier. The black hole is still there, of course, but over the past ten years, it appears to have swallowed all the gas in its vicinity. With the gas consumed, researchers were unable to detect the spectroscopic signature of the quasar, which now appears as an otherwise normal galaxy.
Astronomers using data from NASA’s Fermi Gamma-ray Space Telescope have detected hints of periodic changes in the brightness of a so-called “active” galaxy, whose emissions are powered by a supersized black hole. If confirmed, the discovery would mark the first years-long cyclic gamma-ray emission ever detected from any galaxy, which could provide new insights into physical processes near the black hole.
The baffling and strange behaviours of black holes have become somewhat less mysterious recently, with new observations from NASA’s Explorer missions Swift and the Nuclear Spectroscopic Telescope Array, or NuSTAR. The two space telescopes caught a supermassive black hole known as Mrk 335 in the midst of a giant eruption of X-ray light.
When a star comes too close to the intense gravity of black hole, the resulting tidal forces can rip the star apart. In these so-called tidal disruptions, some of the stellar debris is flung outward at high speeds, while the rest falls toward the black hole, causing a distinct X-ray flare that can last for years. A team of astronomers has observed a tidal disruption event in galaxy PGC 043234 that lies about 290 million light-years from Earth.
Using ESO’s Very Large Telescope, an international team of astronomers have found the hottest and most massive double star with components so close that they touch each other. The two stars in the extreme system VFTS 352 could be heading for a dramatic end, during which the two stars either coalesce to create a single giant star, or form a binary black hole.
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