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Gamma Ray Burst From the Edge of the Universe

Swift\'s Ultaviolet and optical telescope captured a far away gamma ray burst.  Credit: NASA/Swift/Stefan Immler

Swift's Ultaviolet and optical telescope captured a far away gamma ray burst. Credit: NASA/Swift/Stefan Immler

NASA’s Swift satellite captured the most distant gamma-ray burst ever detected. The blast came from an exploding star 12.8 billion light-years away, near the edge of the visible universe. Swift saw the explosion on September 13 at 1:47 am EDT. But because light moves at finite speed, and looking farther into the universe means looking back in time, this means the burst occurred less than 825 million years after the universe began, or when the universe was less than one-seventh its present age. This star was probably from the earliest generations of stars ever formed. “This is the most amazing burst Swift has seen,” said the mission’s lead scientist Neil Gehrels at NASA’s Goddard Space Flight Center.

Gamma rays from the far-off explosion triggered Swift’s Burst Alert Telescope, and the spacecraft established the event’s location in the constellation Eridanus. It quickly turned to examine the spot, and less than two minutes after the alert, Swift’s X-Ray Telescope began observing the position. There, it found a fading, previously unknown X-ray source. The burst has been designated as GRB 080913.

Astronomers on the ground were alerted as well and a group using ESO’s 2.2 meter telescope at the LaSilla Observatory were able to make observations one minute after Swift started observing. An hour and a half later, the Very Large Telescope at Paranal, Chile, targeted the afterglow.

Astronomers look for the redshift of these objects to determine distance. The light that is emitted from an object is shifted towards the red, or less energetic end, of the electromagnetic spectrum, due to the Doppler Effect. In certain colors, the brightness of a distant object shows a characteristic drop caused by intervening gas clouds. The farther away the object is, the longer the wavelength where this fade-out begins.

Analysis of the spectrum for GRB 080913 established the blast’s redshift at 6.7 — among the most distant objects known.

Gamma-ray bursts are the universe’s most luminous explosions. Most occur when massive stars run out of nuclear fuel. As their cores collapse into a black hole or neutron star, gas jets — driven by processes not fully understood — punch through the star and blast into space. There, they strike gas previously shed by the star and heat it, which generates bright afterglows.

Source: NASA


Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.

Comments on this entry are closed.

  • John in Missouri September 22, 2008, 6:25 AM

    Somehow, the posting software left out the last line of my comment, which was a question: Could the universe have had two origin points?

  • genesis continuous September 22, 2008, 2:31 PM

    And the God Murphy said, “I may have missed the handkerchief the first time, but not the second”!

    I guess it’s great sci-fi to suppose there may be two universes – perhaps they are male and female?????


  • Peter September 23, 2008, 7:54 PM


    The universe perportedly started in a phenomenal expansion, not really an explosion. The rate was far greater than the speed of light. The space was expanding as well so nothing moved through space faster than light. Therefore, your math doesn’t apply. It’s like dog-years, the universe got going really fast and then quieted down to it’s present confusing predicament of slow but speeding expansion. I hope that helps.

  • genesis continuous September 24, 2008, 3:35 AM

    Well, I suppose if maths is intended to equate with reason and reason is flawed, we should get reason corrected and then measure up for the maths.

    I could call an event an expansion if it met no resistance over time, but if it slows from a gallop to a trot then it looks more like an explosion, and didn’t it have to overcome inertia to get started?

    Anyway, why do we have to mess around with this crazy man created event that defies logic from beginning to end, when we have more chance of u-turning an oil tanker with a row boat and a piece of string.


  • Chuck Lam September 26, 2008, 3:52 PM

    To: John in MO., Let me have a shot at expalination with my idea of the ‘beginning’ and up through ‘today.’ For starters, imagine what things a hundred billion years ago might have looked like in our vicinity. It probably was a boundless void bubbling with some form of ‘prebang energy’. You and others might ask, why a void and why (prebang) energy? It doesn’t make any sense! Well, stop and think a moment. If no void existed before the B.B, then what does that suggest? It is suggested and often argued that ‘nothing’ existed including time. That could be correct, but ‘nothing’ could be the boundless void spoken of here in this post. And time is nothing more than the of passing events. Time doesn’t have substance and it can’t be measured in three dimensions. It can be argued time didn’t exist in the prebang era. OK, so where did the hypothetical prebang energy come from? Good question, but I don’t know. However, logically it must have existed prior the B.B. because there just had to be seeds of some sort to birth all the matter we see in any direction we look. I believe Einstein’s classic equation covers where the material in the observable universe came from. The B.B. may have not been so big. What we credit the birth and growth of the visible universe to may be nothing more than ‘energy’ (hmm . . . maybe dark energy) morphing into the stuff we see in the universe. This ‘morphing’ could still be going on right in front of us, but we can’t see the trees for the forest. I believe what we are calling the visible universe is a finite small speck in a boundless void. I see a naked simplistic explanation for the creation of the visible universe in Einstein’s E=MC2 formula.

  • Don Alexander September 27, 2008, 10:53 AM

    @Bravehart: With the exception of the red object in the middle, this is a picture from Swift’s UVOT (UltraViolet Optical Telescope). In case of bright stars, it creates weird point-spread functions. To put it bluntly, if a star is too bright, it gets messed up in the picture, creating this weird shape. Nothing to worry about.

    @AstroAl: While there may not seem to be so much difference between 13.7 and 12.8 billion years ago, there’s an enormous difference in redshift. Among other things, redshift describes the shift experienced by electromagnetic radiation, you’ve got that right. This GRB lies at a redshift of 6.7, which means that light at emitted wavelength X is seen at wavelength X * (1+z) = 7.7X here. The surface of last scattering, which produced the CMB, lies at a redshift of about 1250… And 1250 >> 7.7.

    @John in Missouri: Ahem, if you don’t even know how old the Solar System is, maybe you should refrain from thinking about the Big Bang…

  • Richard Diaz October 2, 2008, 8:08 PM

    The energy from a gamma ray burst can be detected even if the telescope is not pointing at it, just like you can detonate a bomb with a remote no matter which way the remote is pointing. Nibiru – if it exists and it’s a rocky or icy planet – only reflects light from the Sun. The energy of light that dim and that far away can’t be detected the same way. The energy isn’t powerful enough for the telescope to detect it if it’s not pointing directly at it and zooming in enough. And the light is so dim, the telescope would only find it if they search until suddenly, so suddenly, they find it in close up like we see Venus with the unaided eye, but dimmer. It would have to be zoomed in enough, because we’re looking for a disc shape, not a twinkling light like a star with it’s corona, which is way larger in appearance than the object.

  • ad koppen October 19, 2008, 4:49 AM

    GRB`s, the most powerfull events in the universe to see, even with the naked eye over billions of light years, what could triggered these events? In my view only the most powerfull energetic bodies, Black Holes, is it possible that 2 dancing around Black Holes pulling energie out of the depths of their holes , until a critical point and then ending in a kind of Black Hole Nova to see trough the universe?, and to create something whole new what we yet have to discover?