PRESS RELEASE - 4 October 2005

Surrey Scientists observe rare celestial event

A rare event on the other side of our Galaxy has produced a massive explosion powerful enough to be seen from Earth. The explosion was the biggest starquake ever observed and surprisingly a tiny neutron star was the source.

A team including scientists from the Mullard Space Science Laboratory (MSSL) in Holmbury St. Mary and Imperial College London have come up with an explanation of how these incredible events can happen.

A neutron star is formed in the final phases of a very massive star's life and represents the dense remnant core. The material is so dense that a teaspoon full on Earth would weigh a billion tonnes. They spin very quickly and have ultra-high magnetic fields, but are also very small. Their diameter is the same as the distance from Guildford to Reigate.

About ten of these neutron stars, called magnetars, are extremely unusual. They are thousands of times more magnetic than ordinary neutron stars and billions of times more magnetic than the most powerful magnets built on Earth. Magnetars can produce sporadic, but huge, explosions which emit radiation in the form of X-rays and gamma rays. The reason for these high energy explosions has been a topic of hot debate.

Dr Silvia Zane who works at MSSL said, "We have observed these very powerful explosions before, but they happen so rarely that we haven't been able to collect enough information to understand them until now."

Crucial observations were made by an instrument which was actually designed to make measurements of particles trapped within the Earth's magnetic field. But processes that occur near our Earth also occur in the far reaches of the Universe.

The instrument, called PEACE, was designed and built at MSSL for a European Space Agency mission called Cluster. The observations have indicated that the giant explosion was formed as the crust of the star cracked in response to huge stresses that built up within due to the rapid rotation. One of the cracks is thought to have been 5km long, which is pretty impressive when the diameter of the star is only around 20km!

Dr Rob Wilson from MSSL said, "When we designed the PEACE instrument we planned to observe processes resulting from the Sun's influence on the Earth. We had no idea we would end up seeing the biggest quake ever produced on a star 50,000 light years away from our own."

If this star had been closer to the Earth, within approximately 10 light years, the blast would have destroyed our normally protective ozone layer and could have caused devasting effects. Luckily the chances of this happening are very small.

MSSL currently has 10 PEACE detectors onboard 2 multi-craft space missions providing a unique opportunity to observe these events.


Notes to Editors

An image accompanying the press release can be found here: http://www.mssl.ucl.ac.uk/~lmg/Press_releases/


Mullard Space Science Laboratory, UCL

MSSL is situated in Holmbury St Mary between Dorking and Guildford, and is the Space and Climate Physics Department of University College London. The Group moved from London to Holmbury St Mary in 1965 after Holmbury House was purchased with funds donated by the Mullard electronics company. 150 scientists work at MSSL across 5 groups; solar and stellar physics, planetary and plasma physics, astrophysics, detector physics and climate physics. The laboratory houses world-class facilities to design, build and test instrumentation as well as analyse the data taken by the instruments in space.



Dr Silvia Zane

Dr Lucie Green

Mullard Space Science Laboratory
Tel: 01483 204100 (Switchboard)




This page last modified 4 October, 2005 by Martin de la Nougerede


Mullard Space Science Laboratory - Holmbury St. Mary - Dorking - Surrey - RH5 6NT - Telephone: +44 (0)1483 204100 - Copyright © 1999-2005 UCL

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