black hole – Astronomy Now

NASA’s Swift mission maps a star’s ‘death spiral’ into a black hole

21 March 2017 Stephen Clark

Some 290 million years ago, a star much like the sun wandered too close to the central black hole of its galaxy. Intense tides tore the star apart, which produced an eruption of optical, ultraviolet and X-ray light that first reached Earth in 2014.

Star discovered in closest known orbit around likely black hole

14 March 2017 Stephen Clark

Astronomers have found evidence for a star that whips around a black hole about twice an hour. This may be the tightest orbital dance ever witnessed for a likely black hole and a companion star.

Our galaxy’s black hole is spewing out planet-size ‘spitballs’

23 January 2017 Stephen Clark

Every few thousand years, an unlucky star wanders too close to the black hole at the center of the Milky Way. The black hole’s powerful gravity rips the star apart, sending a long streamer of gas whipping outward. That would seem to be the end of the story, but it’s not. New research shows that not only can the gas gather itself into planet-size objects, but those objects then are flung throughout the galaxy in a game of cosmic “spitball.”

Spinning black hole swallowing star explains superluminous event

13 December 2016 Astronomy Now

An extraordinarily brilliant point of light seen in a distant galaxy, and dubbed ASASSN-15lh, was thought to be the brightest supernova ever seen. But new observations from several observatories, including ESO and the NASA/ESA Hubble Space Telescope, have now cast doubt on this classification.

A stellar circle of life near Cygnus X-3

22 November 2016 Astronomy Now

A discovery that provides a new way to study how stars form has been captured in a new portrait from NASA’s Chandra X-ray Observatory and the Smithsonian’s Submillimetre Array (SMA). A cloud that is giving birth to stars has been observed to reflect X-rays from Cygnus X-3, a source of X-rays produced by a system where a massive star is slowly being eaten by its companion black hole or neutron star.

Fast radio bursts born in cosmic cataclysms

15 November 2016 Astronomy Now

Fast radio bursts (FRBs) were first discovered in 2007, and in the years since radio astronomers have detected a few dozen of these events. Researchers have found that these mysterious “cosmic whistles” can release a billion times more energy in gamma-rays than they do in radio waves, rivalling supernovae in their explosive power.

Mysterious flaring X-ray objects discovered in nearby galaxies

26 October 2016 Astronomy Now

Astronomers have found a pair of extraordinary cosmic objects that dramatically burst in X-rays, flaring up to become about a hundred times brighter in less than a minute, before returning to original X-ray levels after about an hour. This discovery may represent a new class of explosive events found in space.

Record-breaking extragalactic gamma-ray binary found

30 September 2016 Astronomy Now

Using data from NASA’s Fermi Gamma-ray Space Telescope and other facilities, an international team has found the first gamma-ray binary in another galaxy and the most luminous one ever seen. The dual-star system, dubbed LMC P3, contains a massive star and a crushed stellar core that interact to produce a cyclic flood of gamma rays.

Chandra X-ray Observatory finds evidence for violent stellar merger

16 July 2016 Astronomy Now

Gamma-ray bursts, or GRBs, are some of the most violent and energetic events in the universe. Although these events are the most luminous explosions astronomers can observe, a new study using NASA’s Chandra X-ray Observatory, NASA’s Swift satellite and other Earth-based telescopes suggests that scientists may be missing a majority of these powerful cosmic detonations.

Gravitational vortex provides new way to study matter close to a black hole

14 July 2016 Astronomy Now

The European Space Agency’s orbiting XMM-Newton X-ray observatory has proved the existence of a ‘gravitational vortex’ around a black hole. The discovery, aided by NASA’s NuSTAR mission, solves a mystery that has eluded astronomers for more than 30 years and will allow them to map the behaviour of matter very close to black holes.