accretion disc – Astronomy Now

Black hole sports warped accretion disc, fast-moving jets

7 May 2019 Astronomy Now

Detailed studies of outbursts from a black hole binary reveal a warped accretion disc that triggers skewed polar jets.

Dust clouds may explain emissions from active galactic nuclei

18 June 2018 Astronomy Now

Changes in the light emerging from active galactic nuclei, powered by supermassive black holes, may be explained by clouds of intervening dust that can dim and redden the radiation, eliminating the need for more exotic explanations.

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.

Giant ‘cannonballs’ seen shooting from binary-star system

7 October 2016 Astronomy Now

The NASA/ESA Hubble Space Telescope has detected superhot blobs of gas, each twice as massive as the planet Mars, being ejected near a dying red giant star in the V Hydrae binary system. The plasma balls are zooming so fast through space it would take only 30 minutes for them to travel from Earth to the Moon.

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.

Computer simulations shed light on Milky Way’s missing red giants

8 June 2016 Astronomy Now

New computer simulations from the Georgia Institute of Technology provide a conclusive test for a hypothesis of why the centre of the Milky Way appears to be filled with young stars but has very few old ones. According to the theory, the remnants of older, red giant stars are still there — they just aren’t bright enough to be detected with telescopes.

Clocking the rotation rate of a supermassive black hole

11 March 2016 Astronomy Now

A recent observational campaign involving more than two dozen optical telescopes and NASA’s space-based SWIFT X-ray telescope allowed a team of astronomers to measure very accurately the rotational rate of one of the most massive black holes in the universe. The black hole powers a quasar called OJ 287 which lies about 3.5 billion light-years away from Earth.

VLTI’s sharpest view ever of dusty disc around ageing star

9 March 2016 Astronomy Now

The Very Large Telescope Interferometer at ESO’s Paranal Observatory in Chile has obtained the sharpest view ever of the dusty disc around an ageing star. For the first time such features can be compared to those around young stars — and they look surprisingly similar. It is even possible that a disc appearing at the end of a star’s life might also create a second generation of planets.

High-speed flare observed from supermassive black hole eating star

26 November 2015 Astronomy Now

An international team of astrophysicists has for the first time witnessed a black hole swallowing a star and ejecting a flare of matter moving at nearly the speed of light. The scientists tracked the Sun-sized star in the galaxy PGC 43234 some 300 million light-years away as it shifted from its customary path, slipped into the gravitational pull of the supermassive black hole and was sucked in.

‘Interstellar’ technology throws light on spinning black holes

14 February 2015 Astronomy Now

The team responsible for the Oscar-nominated visual effects at the centre of Christopher Nolan’s epic, Interstellar, have turned science fiction into science fact by providing new insights into the powerful effects of black holes.