Albert Einstein’s general theory of relativity

White dwarf in pulsar binary “drags” space as Einstein predicted

5 February 2020 Astronomy Now

Scientists measure spacetime ‘frame dragging’ around white dwarf by measuring its effects on a companion radio pulsar.

New computer simulation brings black holes to life

26 September 2019 William Harwood

A new computer simulation shows how a black hole’s titanic gravity warps space and bends the light emitted by super-heated debris in a surrounding accretion disc.

Relativity passes another test, this one beyond the Milky Way

22 June 2018 Astronomy Now

Putting general relativity to the test, astronomers compared the known gravity of a galaxy with the bending of spacetime needed to produce a spectacular ‘Einstein ring’ and found, once again, that Einstein was correct.

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.

Seeds of supermassive black holes could be revealed by gravitational waves

27 June 2016 Astronomy Now

Gravitational waves captured by space-based detectors could help identify the origins of supermassive black holes, according to new computer simulations. Durham University’s Institute for Computational Cosmology ran the huge cosmological simulations that can be used to predict the rate at which gravitational waves caused by collisions between the monster black holes might be detected.

NASA balloon mission seeks evidence of cosmological inflation

27 April 2016 Astronomy Now

Now that scientists have confirmed the existence of gravitational waves, a NASA team using a balloon-borne observatory is set to search for a predicted signature of primordial gravitational waves that would prove the infant universe expanded far faster than the speed of light and began growing exponentially almost instantaneously after the Big Bang.

Report of first search for visible light associated with gravitational waves

14 February 2016 Astronomy Now

Catastrophic mergers of binary black holes have been shown to generate gravitational waves, but they can also produce brilliant fireworks of light. Now a team of astronomers has used the Dark Energy Camera (DECam) mounted on the 4-metre Blanco Telescope in Chile in the first detailed search for a visible counterpart of a gravitational wave event.

Magnified image of the faintest galaxy from the early universe

5 December 2015 Astronomy Now

Astronomers harnessing the combined power of NASA’s Hubble and Spitzer space telescopes have found the faintest object ever seen in the early universe. It existed about 400 million years after the big bang, 13.8 billion years ago. The new object is comparable in size to the Large Magellanic Cloud (LMC), a diminutive satellite galaxy of our Milky Way.

Celebrating the golden anniversary of black-hole singularities

2 October 2015 Astronomy Now

When a star collapses forming a black hole, a space-time singularity is created wherein the laws of physics no longer work. In 1965, Sir Roger Penrose presented a theorem where he associated that singularity with so-called ”trapped surfaces” that shrink over time. That hypothesis — one of the results of the general theory of relativity — is now celebrating its 50th anniversary.

Black hole rethink after 11-year cosmic search fails to detect gravitational waves

25 September 2015 Astronomy Now

One hundred years since Einstein proposed gravitational waves as part of his general theory of relativity, an 11-year search performed with CSIRO’s Parkes telescope has shown that an expected background of waves is missing, casting doubt on our understanding of galaxies and black holes.