Institute of Astronomy

Astronomy News

NASA's Hubble Telescope Witnesses Asteroid's Mysterious Disintegration

6 March 2014 - 5:00pm
NASA's Hubble Space Telescope has recorded the never-before-seen break-up of an asteroid into as many as 10 smaller pieces.

Hubble Witnesses an Asteroid Mysteriously Disintegrating

6 March 2014 - 4:00pm

Get larger image formats

Though fragile comet nuclei have been seen falling apart as they near the Sun, nothing like the slow breakup of an asteroid has ever before been observed in the asteroid belt. A series of Hubble Space Telescope images shows that the fragments are drifting away from each other at a leisurely one mile per hour. This makes it unlikely that the asteroid is disintegrating because of a collision with another asteroid. A plausible explanation is that the asteroid is crumbling due to a subtle effect of sunlight. This causes the rotation rate to slowly increase until centrifugal force pulls the asteroid apart. The asteroid's remnant debris, weighing in at 200,000 tons, will in the future provide a rich source of meteoroids.

Rosetta:Rosetta ready for payload check-out

5 March 2014 - 5:41pm
The science and mission operations teams looking after Rosetta have been hard at work in the six weeks since wake up on 20 January 2014. The post-wake-up period ending 2 March has been mainly dedicated to the preparation of the spacecraft for the up-coming payload commissioning phase.

Chandra and XMM-Newton Provide Direct Measurement of Distant Black Hole's Spin

5 March 2014 - 5:00pm
Astronomers have used NASA's Chandra X-ray Observatory and the European Space Agency's (ESA's) XMM-Newton to show a supermassive black hole six billion light years from Earth is spinning extremely rapidly. This first direct measurement of the spin of such a distant black hole is an important advance for understanding how black holes grow over time.

First Light for MUSE

5 March 2014 - 12:00pm
A new innovative instrument called MUSE (Multi Unit Spectroscopic Explorer) has been successfully installed on ESO’s Very Large Telescope (VLT) at the Paranal Observatory in northern Chile. MUSE has observed distant galaxies, bright stars and other test targets during the first period of very successful observations.

Reflection from the strong gravity regime in a lensed quasar at redshift z = 0.658

5 March 2014 - 1:00am

Reflection from the strong gravity regime in a lensed quasar at redshift z = 0.658

Nature 507, 7491 (2014). doi:10.1038/nature13031

Authors: R. C. Reis, M. T. Reynolds, J. M. Miller & D. J. Walton

The co-evolution of a supermassive black hole with its host galaxy through cosmic time is encoded in its spin. At z > 2, supermassive black holes are thought to grow mostly by merger-driven accretion leading to high spin. It is not known, however, whether below z ≈ 1 these black holes continue to grow by coherent accretion or in a chaotic manner, though clear differences are predicted in their spin evolution. An established method of measuring the spin of black holes is through the study of relativistic reflection features from the inner accretion disk. Owing to their greater distances from Earth, there has hitherto been no significant detection of relativistic reflection features in a moderate-redshift quasar. Here we report an analysis of archival X-ray data together with a deep observation of a gravitationally lensed quasar at z = 0.658. The emission originates within three or fewer gravitational radii from the black hole, implying a spin parameter (a measure of how fast the black hole is rotating) of a = at the 3σ confidence level and a > 0.66 at the 5σ level. The high spin found here is indicative of growth by coherent accretion for this black hole, and suggests that black-hole growth at 0.5 ≤ z ≤ 1 occurs principally by coherent rather than chaotic accretion episodes.

Astrophysics: Cosmic lens reveals spinning black hole

5 March 2014 - 1:00am

Astrophysics: Cosmic lens reveals spinning black hole

Nature 507, 7491 (2014). doi:10.1038/nature13209

Authors: Guido Risaliti

The power of a cosmic lens to magnify and split the light from a distant, mass-accreting giant black hole into four components has allowed researchers to measure the black hole's spin. See Letter p.207

Hubble:Spiral galaxy spills blood and guts [heic1404]

4 March 2014 - 4:43pm
This new Hubble image shows spiral galaxy ESO 137-001, framed against a bright background as it moves through the heart of galaxy cluster Abell 3627. This cluster is violently ripping the spiral's entrails out into space, leaving bright blue streaks as telltale clues to this cosmic crime.

Life Is Too Fast, Too Furious for This Runaway Galaxy

4 March 2014 - 4:00pm

Get larger image formats

Our spiral-shaped Milky Way galaxy lives in a comparatively quiet backwater region of the universe. This is not the case for galaxies crammed together inside huge clusters. As they zip around within a cluster, gas can be pulled from their disks due to a process called ram pressure stripping. Galaxy ESO 137-001 is one example. The star-city looks like it is "leaking" as it plunges through the Norma galaxy cluster.

This week, 1-8 March, is National Astronomy Week. Join in by counting the numbe...

4 March 2014 - 3:47pm
This week, 1-8 March, is National Astronomy Week.

Join in by counting the number of stars you can see in Orion, which helps scientists measure light pollution:

Star Count 2014 | National Astronomy Week 2014
NAW 2014 has joined forces with the Campaign to Protect Rural England (CPRE) and the British Astronomical Association’s Campaign for Dark Skies to monitor the extent of light pollution.

Gaia tilt watched from Earth

4 March 2014 - 1:28pm

As part of the tests to try and diagnose the stray light issue noticed in the first month of instrument commissioning, the Gaia operations team is making a series of spacecraft orientation changes.

The spacecraft was first tilted from 45 to 42 degrees and then to 0 degrees, that is, facing its sunshield directly at the Sun. Then the spacecraft was returned to 45 degrees.

Gaia tilt seen from Earth

Astronomers Peter Veres and Bryce Bolin, who were following a call for Earth-bound observations to improve the prediction of Gaia’s brightness under different viewing conditions, used the 2.24m  telescope on Mauna Kea in Hawaii to capture Gaia’s tilt from 0 to 45 degrees on 27 February.

The resulting movie nicely illustrates the change in brightness of the spacecraft over a period of around half an hour (12:14:52 UT to 12:42:06 UT), as Gaia’s sunshield tilted away from the Earth. Gaia is the bright object in the centre of the movie and moves downwards.

Dave Tholen, who processed the images, said: “We started with 10 second exposures for the first 30 exposures, then increased the exposure time to 20 seconds to get images 31 to 35, then increased again to 40 seconds for images 36 to 40. The last three exposures were 80 seconds each.”

The observations also captured a main belt asteroid (2002 RS34) moving from top centre to the right of the field of view in the movie.

As for the issue of stray light, the data are still being analysed. The tilting process will be repeated again, at a much slower rate, in order to gather more information from on-board systems during the transition period.

National Astronomy Week starts tomorrow, and runs from 1-8 March. Over 160 even...

28 February 2014 - 12:33pm
National Astronomy Week starts tomorrow, and runs from 1-8 March.

Over 160 events are happening throughout the UK. There's a map and search tool on

See also our press release:

National Astronomy Week 2014
All eyes will be on the skies between 1st and 8th March 2014 when an array of fascinating celestial objects will be gathered in the night sky. Throughout the week, astronomical organisations and societies all over the UK will be holding a host of special observing events open to the public. This is ...