Supernova captured in 'real time'
The shockwave bursts through the star's surface, releasing it s energy
Astronomers say they have
witnessed a stellar explosion - or supernova - unfolding in real time.
Supernovae occur when a huge, mature star effectively runs out of fuel and collapses in on itself.
Their observations, outlined in the journal Nature, offer the most detailed picture yet of these cosmic explosions.
An initial release of energy from the star was picked up by the US Swift satellite in February, allowing experts to train their telescopes on the event.
This short, sharp outburst, known as an X-ray flash, is effectively an early warning signal that the star was going to turn supernova.
Swift is designed to look out for gamma-ray bursts (GRBs), intense energetic outbursts of radiation thought to arise from the collapse of massive stars in a supernova. However, not all supernovae generate GRBs, and it remains unclear what causes some but not others to produce these bursts.
Compact remnant
An X-ray flash can be regarded as a less energetic form of GRB. It was previously unclear whether these less energetic events were generated by the same process of stellar collapse during a supernova. The latest results seem to confirm that link.
The release of energy that occurs in the X-ray flash lasts for about 15 minutes and is followed by a day-long "breakout" phase, in which the shockwave breaches the surface of the collapsing star, unleashing its energy.
The stellar explosion occurred 400 million light years away
This expands into space as radiation at all frequencies and lasts for a period of days to months - the classic signature of a supernova.
Four groups of astronomers gathered data on the event, and publish separate research papers in Thursday's issue of Nature.
"Those observations capture the time when the star collapsed, ejected its outer envelope and most of its mass and left a compact remnant behind. And we think that compact remnant is a neutron star," said Paolo Mazzali, one of the authors who is based at the Max-Planck Institute in Garching, Germany.
Analysis of the expanding debris suggests the initial star had a lower mass than is the norm for such explosions. Gamma-ray bursts are thought to be associated with the collapse of a star into a black hole. But lower mass stars are thought to collapse into a compact object known as a neutron star. So what powered the X-ray flash and shockwave? The researchers think these were produced by magnetic energy supplied by a highly magnetised object at the core of the star called a magnetar.
Astronomers say they have
witnessed a stellar explosion - or supernova - unfolding in real time.
Supernovae occur when a huge, mature star effectively runs out of fuel and collapses in on itself.
Their observations, outlined in the journal Nature, offer the most detailed picture yet of these cosmic explosions.
An initial release of energy from the star was picked up by the US Swift satellite in February, allowing experts to train their telescopes on the event.
This short, sharp outburst, known as an X-ray flash, is effectively an early warning signal that the star was going to turn supernova.
Swift is designed to look out for gamma-ray bursts (GRBs), intense energetic outbursts of radiation thought to arise from the collapse of massive stars in a supernova. However, not all supernovae generate GRBs, and it remains unclear what causes some but not others to produce these bursts.
Compact remnant
An X-ray flash can be regarded as a less energetic form of GRB. It was previously unclear whether these less energetic events were generated by the same process of stellar collapse during a supernova. The latest results seem to confirm that link.
The release of energy that occurs in the X-ray flash lasts for about 15 minutes and is followed by a day-long "breakout" phase, in which the shockwave breaches the surface of the collapsing star, unleashing its energy.
This expands into space as radiation at all frequencies and lasts for a period of days to months - the classic signature of a supernova.
Four groups of astronomers gathered data on the event, and publish separate research papers in Thursday's issue of Nature.
"Those observations capture the time when the star collapsed, ejected its outer envelope and most of its mass and left a compact remnant behind. And we think that compact remnant is a neutron star," said Paolo Mazzali, one of the authors who is based at the Max-Planck Institute in Garching, Germany.
Analysis of the expanding debris suggests the initial star had a lower mass than is the norm for such explosions. Gamma-ray bursts are thought to be associated with the collapse of a star into a black hole. But lower mass stars are thought to collapse into a compact object known as a neutron star. So what powered the X-ray flash and shockwave? The researchers think these were produced by magnetic energy supplied by a highly magnetised object at the core of the star called a magnetar.
