Enormous eruption reveals dead star in deep space

June 17th, 2009 - 12:21 pm ICT by ANI  

Paris, June 17 (ANI): Astronomers, using ESA’s (European Space Agency’s) XMM-Newton and Integral space observatories, have observed an enormous eruption, which after careful analysis, has revealed a dead star belonging to a rare group: the magnetars.

X-Rays from the giant outburst arrived on Earth on August 22, 2008, and triggered an automatic sensor on the NASA-led, international Swift satellite.

Just twelve hours later, XMM-Newton zeroed in and began to collect the radiation, allowing the most detailed spectral study of the decay of a magnetar outburst.

The outburst lasted for more than four months, during which time hundreds of smaller bursts were measured.

“Magnetars allow us to study extreme matter conditions that cannot be reproduced on Earth,” said Nanda Rea, from the University of Amsterdam, who led the team that performed the research.

Magnetars are the most intensely magnetised objects in the Universe. Their magnetic fields are some 10,000 million times stronger than Earth’s.

If a magnetar were to magically appear at half the Moon’s distance from Earth, its magnetic field would wipe the details off every credit card on Earth.

This particular magnetar, known as SGR 0501+4516, is estimated to lie about 15,000 light-years away, and was undiscovered until its outburst gave it away.

Only five days after the big eruption, Integral detected highly energetic X-rays coming from the outburst, beyond the energy range that XMM-Newton can see.

It is the first time such transient X-ray emission has been detected during the outburst.

It disappeared within 10 days and was probably generated as the magnetic configuration changed.

Magnetar outbursts can supply as much energy to Earth as solar flares, despite the fact they are far across our Galaxy, whereas the Sun is at our celestial doorstep.

There are two ideas as to how a magnetar forms.

One is that it is the tiny core left behind after a highly magnetic star has died. But, such magnetic stars are very rare, with just a few known in our Galaxy.

Another suggestion is that during the death of a normal star, its tiny core is accelerated, providing a dynamo that strengthens its magnetic field, turning it into a magnetar.

Currently, most astronomers favour the first idea but as yet they have no conclusive proof.

“If we could just find a magnetar in a cluster of highly magnetic stars, that would prove it,” said Rea. (ANI)

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