Ultraviolet gives view inside real 'death star'

Jun 13, 2008
Ultraviolet gives view inside real 'death star'
Flash of ultraviolet light revealing the death throes of a star.

Scientists have, for the first time, observed a flash of ultraviolet light from within a dying star giving vital evidence of how stars turn into supernovae.

An international team, including nine scientists from Oxford University, combined data from ground-bound telescopes observing visible light from supernovae with data from a space telescope looking for an earlier peak in ultraviolet light from an associated dying star. They were able to spot telltale signs of the shockwave that forms within a star before it explodes into a supernova. A report of the work appears in this week’s Science.

‘Supernovae are huge stellar explosions that light up galaxies but often we have no idea which star has exploded,’ said Dr Kevin Schawinski of Oxford University’s Department of Physics. ‘The nature of such an explosion is that we can’t look inside it and it destroys almost all evidence of the original star – scientists have been trying to catch such an event happening for decades.’

Previously, scientists have observed stars nearing the end of their lives and supernova explosions and their afterglow, but have had little firm evidence of what happens in between. The new observations give a first glimpse of what happens inside a star during its final hours of life.

‘Out of all the supernovae we looked at we found one that was preceded by a dramatic ‘flash’ of ultraviolet light given off by a red super-giant star in a galaxy around a billion light years away. This flash occurred about two weeks before it was detected as a normal supernova,’ said Dr Stephen Justham of Oxford University’s Department of Physics.

‘We believe that this light, emanating from deep within the star, was generated after its core collapsed and compressed the gas surrounding it to around one million degrees Kelvin.’ Around four hours after this light was observed a shockwave from the collapsed core, travelling at 50 million kilometres an hour, would have hit the surface of the star and blown it apart. However, it was almost two weeks before the resulting fireball was spotted by supernova hunters using telescopes in Hawaii.

‘With this observation we have managed to peer inside one of the hundred billion stars in a galaxy and see what it is like at the very moment that it dies,’ said Dr Christian Wolf of Oxford University’s Department of Physics. ‘We’ve been extremely fortunate to capture this moment but this is just one event and, of course, we’d love to capture other similar events with different stars which could deliver many more surprises.’

Source: Oxford University

Explore further: WISE spacecraft discovers most luminous galaxy in universe

Related Stories

Recreating the heart of a star on Earth

Mar 24, 2015

By recreating the extreme conditions similar to those found half-way into the Sun in a thin metal foil, Oxford University researchers have captured crucial information about how electrons and ions interact in a unique state ...

Black hole trio holds promise for gravity wave hunt

Jun 25, 2014

The discovery of three closely orbiting supermassive black holes in a galaxy more than four billion light years away could help astronomers in the search for gravitational waves: the 'ripples in spacetime' ...

Recommended for you

Hubble observes one-of-a-kind star nicknamed 'Nasty'

May 21, 2015

Astronomers using NASA's Hubble Space Telescope have uncovered surprising new clues about a hefty, rapidly aging star whose behavior has never been seen before in our Milky Way galaxy. In fact, the star is ...

Galaxy's snacking habits revealed

May 20, 2015

A team of Australian and Spanish astronomers have caught a greedy galaxy gobbling on its neighbours and leaving crumbs of evidence about its dietary past.

Supernova ignition surprises scientists

May 20, 2015

Scientists have captured the early death throes of supernovae for the first time and found that the universe's benchmark explosions are much more varied than expected.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Mercury_01
1 / 5 (1) Jun 13, 2008
Wheres the exhaust port?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.