Gamma Ray Burst From the Edge of the Universe
Written by Nancy Atkinson
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
Filed under: Gamma Ray Bursts
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September 20th, 2008 at 8:40 am
". . . . 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."
Hate to be a nitpicker but when I do the math I get a considerably smaller percentage of the total age of the universe:
13.7 Byr / .825 Byr = 16.6
What am I missing?
All that aside a very interesting event. I'm curious about how much time we might generally expect such a stars evolution to require.
Also, applying the inverse-square law with a radius of 12.8 Billion light years!!! Well our language really has no words.
September 20th, 2008 at 10:57 am
Well, if they can detect a GRB that far away in the universe but can't even detect supposed Nibiru in our own galaxy, tell me what the hell is blocking "Nibiru" from sight.
September 20th, 2008 at 11:02 am
Joe M. –
You can't see something that's not there.
September 20th, 2008 at 11:13 am
That's god after a bad meal.
September 20th, 2008 at 11:19 am
What's a Nibiru?
September 20th, 2008 at 11:30 am
According to wikipedia: Nibiru is a pseudoscientific planetary object, described by Zecharia Sitchin.
September 20th, 2008 at 11:43 am
Approximate observed intensity of the GRB at the stated distance – not accounting for any interim effects:
1/163,840,000,000,000,000,000. of original source intensity.
I'm glad I wasn't in the neighborhood when that firecracker went off! Hurricane Ike was bad enough for me.
September 20th, 2008 at 3:52 pm
And I have scientific proof that the god Murphy created the universe last thursday when he sneezed and missed his handkercheif.
He and the flying spaghetti monster (all hail his noodly appendages) tried to correct the problems they saw coming, but it was too late.
September 20th, 2008 at 6:25 pm
Fraser, I ToSeek'ed you (and the BA) on the day of the GRB.
Check into BAUTforum.com every once in a while.
Okay, of course, you are basing this on an official press release.
At least you, in contrast to the BA, mentioned the observations by "ESO's 2.2m telescope at [La Silla] observatory". It was this telescope that – as the press release correctly states – which first discovered the afterglow and established its extreme redshift photometrically. That triggered the VLT observing program.
September 21st, 2008 at 5:35 am
"Gamma ray burst from the edge of the universe." Can't help wonder if the edge of the observable universe is simply the 'expansion' (we think exists) reaching the finite speed limit of light. Maybe there is nothing more than the same of all we can see in any direction beyond this maximum redshift. Maybe the 'big bang' is a local prebang energy morph into matter with a 13 billion something light year radus. Maybe we are looking at the origin of the universe all wrong.
September 21st, 2008 at 6:54 am
…trying to wrap my brain around the numbers is giving me an ice cream headache.
Can't think of any coherent comment except to wonder at the odds of a star from the other side of the universe going off way back then and the light only reaching here now. Right on target for our world.
Its almost a worthy plot device for a sci-fi novel.
September 21st, 2008 at 12:31 pm
So all these GRb's and where is GLAST/Fermi? I thought G/F could spot GRB's tout de suite and do some serious pix/analysis/science.
September 21st, 2008 at 2:24 pm
Getting one's head around the maths might be why the god Murphy missed his handkerchief. But that's not all.
If the universe is expanding at an incredible rate then 'missing the handkercief makes sense, because what we see just isn't there now, is it? Won't the youngest galaxies in the universe be billions and billions of light years further away by now? And will that burst be visible from 12.8 billion light years away beyond where it was. Light shines globally, one would think. Oh my goodness, conservation within our limited cosmic containment has just 'gone out the back door' !
David
September 21st, 2008 at 4:53 pm
@Maxwell
"Its almost a worthy plot device for a sci-fi novel."
I recently read a Sci Fi Novel called Blue Light by Walter Mosley a very interesting read about a strange light that fell on the Earth and affected people in remarkable ways. It's a fantasy really and very well written. I'd recommend it to everyone.
September 21st, 2008 at 5:14 pm
Forgive the extra post but I found a good discription of the novel I wanted to share.
Blue Light (1998)
". . . . Blue Light, is Walter Moseley's first scifi novel and the prelude to a trilogy. From an unknown point in the universe, an inscrutable blue light approaches our solar system. When it reaches Earth, it transforms those it strikes, causing them to evolve beyond the present state of humanity. Each person imbued with the light becomes the full realization of his or her nature and potential, with strengths, understanding, and communication abilities far beyond our imagining."
September 21st, 2008 at 7:21 pm
I wonder what it would be like to see a GRB caused by the formation of a super massive black hole. The GRB would be about 13.2+ billion years old to coincide with galaxy formation in the early universe.
On the other hand, if we see only one or so regular GRB's per day out of the billions of stars of billions of galaxies, then I guess we would witness the GRB from a SMBH formation less than once every billion days, or less than once in 2,740,000 years.
That would be one hell of a blast. I realize that measuring the afterglow from a GRB is easier to do because of reaction time following detection and is an indirect measure of the blast itself. Can we measure the GRB directly to calculate the mass of the black hole that was formed?
September 21st, 2008 at 7:28 pm
Just wonder what that diamond figured object
is at the bottom of the picture?
Looks odd?
September 22nd, 2008 at 5:13 am
If gamma rays from the Big Bang (13.5 billion light years) have red-shifted to microwaves (CMB), how come we can see gamma rays from 12.8 billion light years away? Shouldn't these be red-shifted to microwaves?
September 22nd, 2008 at 6:23 am
Okay, this is a perfect illustration of a question I have asked time and again, and even Fraser and Pamela have not answered it to my satisfaction. This event occurred 825 million years after the Big Bang (or whatever). Assuming that we all came from a grain of superdense whatever that exploded outward at the beginning of time, and making an assumption for argument's sake that the first 825 million years that all matter flew apart at the speed of light (remember this is for argument's sake), then the furthest away that this thing could have happened was (assuming diametric opposition) was 1billion 650 million from earth (which probably didn't exist at that time–heck, our SUN probably didn't exist that early in the game). So how could something be happening so far away from us, so far back in time? Could our universe have two origin points?
And for the record, folks, though I am a person of faith, I believe the scientists when they say the universe is about 13 to 15 billion years old…I am not trying to start a religious argument. My conception of the Big Bang is obviously wrong, and I am trying correct it.
September 22nd, 2008 at 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?
September 22nd, 2008 at 12:48 pm
This will probably sound ridiculous but…
You could argue that if space-time is curved and you were at the exact center of the universe at creation, then looking to either side you could see yourself at your current position. So from a certain perspective you could say that given a certain location and time it could appear as though there were 2 simultaneous creation events. Though that's basically just a perspective issue and not really possible at all. "What if" thought experiments are fun!
September 22nd, 2008 at 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?????
David
September 23rd, 2008 at 7:54 pm
John,
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.
September 24th, 2008 at 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.
David
September 26th, 2008 at 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.
September 27th, 2008 at 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…
October 2nd, 2008 at 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.
October 19th, 2008 at 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?