Most Extreme Gamma-Ray Blast Yet Detected 128
Matt_dk sends in a quote from a story at NASA:
"The first gamma-ray burst to be seen in high-resolution from NASA's Fermi Gamma-ray Space Telescope is one for the record books. The blast had the greatest total energy, the fastest motions and the highest-energy initial emissions ever seen. ... Gamma-ray bursts are the universe's most luminous explosions. Astronomers believe most occur when exotic massive stars run out of nuclear fuel. As a star's core collapses into a black hole, jets of material — powered by processes not yet fully understood — blast outward at nearly the speed of light. The jets bore all the way through the collapsing star and continue into space, where they interact with gas previously shed by the star and generate bright afterglows that fade with time. ...Fermi team members calculated that the blast exceeded the power of approximately 9,000 ordinary supernovae, if the energy was emitted equally in all directions."
Flash me? (Score:2)
And this isn't a Men in Black flashing device?
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WHAT'S THE SCOUTER SAY ABOUT THIS SUPERNOVA? (Score:5, Funny)
IT'S OVER NINE THOUSAAAAAND~
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This seems several orders of magnitude beyond most of the energy measurement terms I'm familiar with. One could use scientific notation, but for a few of us, X to the Xtillionth GigaJoules is a little too abstract. This is not too ambiguous for me.
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"Fermi team members calculated that the blast exceeded the power of approximately 9,000 ordinary supernovae, if the energy was emitted equally in all directions." IT'S OVER NINE THOUSAAAAAND~
I was hoping for a great set of comments to read, but now I have to pick and choose to get to the informative comments--all because of this number. ;(
coloured dots!!! (Score:1)
WOAHH!!!
This is called humour, oh Spock descendant mods
yes i see the time problem in my statement
Re:coloured dots!!! (Score:4, Insightful)
And make it relative! (Score:2)
I'd go one further. That very same graph with a third axis (axee? axen? Arg!) that shows this burst/time graph relative to an energy source I can somewhat comprehend. Maybe the projected output of an average star over that same time frame.
P.S. - Great sig. I actually LOL'ed.
Re:And make it relative! (Score:4, Informative)
That very same graph with a third axis (axee? axen? Arg!) that shows this burst/time graph relative to an energy source I can somewhat comprehend.
The plural of axis is axes.
That said, you're talking about a single one (the third in a set, but it's still singular) so axis is correct.
Re:And make it relative! (Score:5, Funny)
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More like narrow chisels.
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P.S. - Great sig. I actually LOL'ed.
Its not mine though. Years ago there was a magazine called Kilobaud Microcomputing. In one issue they ran a funny graphic story called "The man from CPU". It was a detective story built around computer jargon. By the time I realised the value of it my Dad had cleared out the attic and all the old magazines were gone. From time to time I google a few choice keywords in the hope that somebody has put their archives on line and I can recover the article.
So far it has been no go but I put that line in my sig
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I remember that magazine, although I never saw that particular article. Sounds like a real gem.
You ought to contribute that to the wiki article on KM. Perhaps somewhere out there someone still has some old mags... I've seen a few issues for sale on ebay from time to time.
Cheers,
SB
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http://arxiv.org/abs/0902.0761 [arxiv.org]
Submitted by the leader of the team working with GROND.
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"9,000 ordinary supernovae" = 9000 x 10^44 Joules =~ 10^48 Joules.
According to Wikipedia, 1 ton (do they mean tonne) of TNT = 4 x 10^9 Joules, so this makes 2 x 10^38 tons of TNT equivalent.
And the largest bomb ever exploded is 5x10^8 tons of TNT.
So this would be ~ 10^30 of those, or around a million Yotta-bombs.
Not sure if that helps.
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If a tonne of TNT goes "Boom!", and six tonnes goes "Booooooom!" (etc) then to type this noise out would take 1,000,000,000,000,000,000,000,000,000,001 o's.
Nope. Doesn't help either.
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What interests me is if this explosion had occurred anywhere in the milky way galaxy and the energy was directed at earth, would we still be here discussing the matter?
Depends. Is slashdot accessible from the afterlife?
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And the largest bomb ever exploded is 5x10^8 tons of TNT.
Not quite. You are thinking of the sowjet "Tsar Bomba" [wikipedia.org] - with an estimated
blast of about 50Mt TNT-equivalent. That would be 50e6, or 5*10^7.
This factor of ten of yours of course doesn't change the fact that the amounts of energy involved in cosmic
explosions are mindbogglingly huge.
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Actually, it is worse. It is a 6-second .mov Quicktime movie, all 7 MB of it. Considering it is a 6-second movie of colored dots, it would have been a lot more efficient to represent it in a different format. Perhaps an animated GIF?
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Your tax dollars at work eh? Paying for NASAs servers to withstand a Slashdotting of an excessively large movie.
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Not even close. The universe extends so far in every direction that no matter where you look, you get objects receding from you at the speed of light.
On the upside though, congratulations! You are once again at the center of the known universe.
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....you get objects receding from you at the speed of light.....
From the article: ...Astronomers believe most occur when exotic massive stars run out of nuclear fuel....
Who cares what astronomers believe, rather what they know. Many of them also still believe your statement above. They believe this because of an underlying belief that the red shift is caused by movement rather than effects arising in the atoms emitting the observed light. Back in 1929, when Edwin Hubble first observed the red shift he tenta
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...You're a moron....
In any discussion on any subject, the party that resorts to personal attack and name calling is automatically admitting defeat.
Re:Big Bang (Score:4, Insightful)
"quantized" red shift.
You don't even know enough to know you don't know what the hell you're talking about.
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The universe extends so far in every direction that no matter where you look, you get objects receding from you at the speed of light.
Just to be clear, the highest redshift object is galaxy IOK-1 [wikipedia.org] with a redshift of z = 6.96, which is nowhere near high enough for the object to be moving away from us at nearly the speed of light.
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That light left that galaxy 12.88 billion years ago, when the universe was 750 million years old. The universe is expanding, and has been for all of those nearly 13 billion years. Whatever distance this object was then, it's a good country mile further down the road now. It's reasonable to expect that light leaving it today will never arrive here because the relative vectors currently exceed the speed of light, or will before it arrives here. The Y'krith of IOK-1/septus/keorf/3 have left our light cone.
Re:Big Bang (Score:4, Informative)
No, this was just a little Bang. The big one, we had already found. You can see a picture here [nasa.gov].
how do they know (Score:1)
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Parallax and red shift, I would imagine. They know the speed of light, and the rate (roughly) that red-shifting happens. Parallax measurements allow them to determine how far away it is to at least a modicum of accuracy.
Note: The above is a guess, but it seems plausible.
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Parallax and redshift perhaps?
Parallax only works to about 1600 light years, which is aprox 1% of the diameter of our Galaxy. And that is with a specialized satellite doing the measurement. There is no way parallax is going to work for something that is 12.2 billion light-years away.
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parallax only works for stars very close (astronomically speaking) to us... few dozen light-years at most. Even then they have to use the whole width of earth's orbit around the sun, taken 6 months apart, to calculate the parallax.... closing your left eye then your right eye aint gonna cut it for measuring light-year distances :P
Redshift is how they measure galaxy distances, and by some process they determine that this gamma ray burst occurred in galaxy X, so that's how far they come up with the distance h
Re:how do they know (Score:4, Informative)
The host or counterpart galaxy was too faint (the GRB was 12.8Gly away, and models predict that the host galaxy wouldn't be detectable). But apparently, there is now enough confidence in the models for GRBs to get a good fix on the distance anyway. It's awesome that they can do this without observing a host galaxy now.
The same team that measured this also confirmed the most distant GRB to date last September, and this is within the most distant 5% of observed GRBs.
Arxiv paper [arxiv.org]
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GROND (Score:3, Informative)
In this particular case, it was this [eso.org].
Method is explained a little in the eso.org link, but here's a wikipedia article, too: http://en.wikipedia.org/wiki/Photometric_redshift [wikipedia.org].
Also, awesome Tolkien reference apparently acknowledged by Jochen Greiner.
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Wow, that's obscure [wikipedia.org]!
Re:how do they know (Score:5, Informative)
i've always wondered how they know the size and distance of these objects. short of running a tape measure out, how the hell do you calculate the size of something an unknown distance away?
The chain of logic is vast and complex, but I'll try to summarize:
1) First, we used radar and the speed of light to figure out the distances of things in our solar system. These calculations helped us figure out the diameter of the Earth's orbit, which is used in the next step, parallax.
2) Once we know the diameter of Earth's orbit, we used parallax to determine the distance to nearby stars. Parallax is a process of triangulation, where we use the earth at two extremes and the star we are looking at as the three points of a triangle. Knowing two angles and one side lets us solve for the distance to the star. But the resolution of our telescopes only lets us use this method with any accuracy for stars in our immediate vicinity.
3) Once we could figure our how far away nearby stars are, we began focusing in on types of stars that have fairly consistent outputs of energy in comparison to their other measurable traits, such as color. We call these consistent types of stars (and other astronomical objects) standard candles.
4) Once we are sure that these standard candles do indeed have consistently predictable outputs, we can guess how far away stars of these types are by noting that luminosity (total light output) and apparent brightness are related by a simple inverse distance squared relationship. This lets us estimate the distance to any type of star that has a fairly estimable luminosity.
5) After we have our standard candles mapped out in space, we can note the absorption lines in the light spectrum which indicates various types of dust and gasses. With this data we can make a rough map of where dust and gasses are floating around. This map will let us look at light from stars and objects that aren't standard candles and figure out how far away they should be to account for the absorption lines we see in their light spectrum.
6) After mapping out many of the nearby galaxies using supernovae as our key standard candle, we notices that is seems that there is a linear correlation between how far away an object is and how fast it is moving away from us (we can tell how fast an object is moving away from us using red-shift). This observation seems to show that the universe is expanding, but more important to the discussion at hand, it gives us another tool with which to estimate and map the distances of objects -- this time at any arbitrary distance.
Using the many of the above methods we can get estimates for how far away objects are, but the margin of error is huge because of all of the assumptions we've made. Plus of minus a magnitude or two is considered fairly precise in astronomical terms. This might have been more of an answer than you bargained for, but there you have it.
Re:how do they know (Score:5, Insightful)
Re:how do they know (Score:5, Informative)
I don't think you made the part about standard candles very clear, so I'll elaborate on that point.
The term doesn't refer to a specific type of star. Standard candles are any stellar objects that have some quality that allows them to be used to measure distance.
One of the most famous examples are Cepheid variable stars. These stars all vary in brightness over some predictable period of time. There is a relationship between how fast they "pulse" and how bright they are. The faster they pulse, the dimmer they are (in absolute terms). If one is pulsing really slow, and it looks dim (relatively speaking), it's probably very far away since it should be relatively bright. If it looks bright and pulses quickly, it's probably close by since they don't get very bright (absolutely speaking).
Other standard candles include planetary nebula, supergiants, globular clusters, H II regions, and supernova. Each of them has a different maximum range over which they can be detected, but there is some overlap. The ones in the overlapping regions are used to calibrate the distances for the rest.
Don't forget about SN_1987 (Score:1)
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yep, thank you! ...and I wonder why this story is tagged !etacarinae
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I hope I won't get whooshed for this, but the !etacarinae tag is because the popular science articles said it was in the direction of the constellation Carina. There is a famous hypergiant in that direction, about 7.5Kly away from us called Eta Carinae [wikipedia.org], which is expected to supernova in the near future (astronomically near, anyway) and produce a GRB.
GP's post is fine and all, but the determination of the distance of this is just as interesting as its extreme intensity. The host galaxy was too faint to be de
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For those not familiar with Eta Carinae, you need to check out the Eta Carinae nebulae (one of the largest nebulae of it's kind in our neck of the galaxy, and the star itself which puffs out huge amounts of gas and dust. The current dual lobed cloud surrounding the star if brightly illuminated by it, and referred by astronomers as the Homunculus (latin for little human or puppet.) Because the cloud seen through a telescpe looks vaguely like a little doll.
If this star does go with a gamma ray burst, and if o
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Correction, a very bad LAST day. I for one am damned glad we are looking at that thing from the angle we are. And I hope it or we don't move so that when it does blow, we are looking down the gun barrel. The GRB will be here from that distance, probably within a few days of seeing it go supernova. The question that runs in the back of my alleged mind is: Are these GRB's beamed, or isotopic. If beamed, and we are in the beam...
Not much we can do but make our peace.
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The gamma rays will be the first thing to arrive after the neutrinos.
http://en.wikipedia.org/wiki/SN1987A#Neutrino_emissions [wikipedia.org]
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Correction, a very bad LAST day. I for one am damned glad we are looking at that thing from the angle we are. And I hope it or we don't move so that when it does blow, we are looking down the gun barrel. The GRB will be here from that distance, probably within a few days of seeing it go supernova. The question that runs in the back of my alleged mind is: Are these GRB's beamed, or isotopic. If beamed, and we are in the beam...
Not much we can do but make our peace.
Wouldn't the GRB be here at the exact same m
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Parent is essentially correct and thorough but one thing I'll add is the importance of supernova as standard candles.
A certain type of supernova - Type Ia [wikipedia.org] is always going to peak at the same absolute brightness because of the physical process involved. It is the result of one star - a white draw - drawing in matter from another star until the white dwarf reaches a mass where it can no longer keep itself from collapsing. As a result it implodes and bounces back as a spectacular supernova explosion. Since the
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> 1) First, we used radar and the speed of light to figure out the distances of things in
> our solar system. These calculations helped us figure out the diameter of the Earth's
> orbit, which is used in the next step, parallax.
No. First we used Newton's laws and geometry to figure out the distances of things in our solar system. No radar needed. The first quantitative estimates of the speed of light were made using the known motion of and distance to Jupiter's moon Io.
Need for a bigger parallax? (Score:4, Interesting)
That's enormously interesting.
It seems to me that, if funding were available, one of the most useful things for astronomy then would be a set of ships sent to "opposite" orbits in the solar system, extremely far from the sun. Given today's technology, the farther you could get a pair of ships orbiting at an extreme distance from the sun - out past jupiter and farther, then, you could extend the range of your parallax measurements, which are fairly direct. You'll never obviously be able to get the whole universe, but you would be able to get more standard candles. Or, are there already enough stars within a thousand light years that you don't need that? A thousand light years is a pretty good chunk of space.
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Re: 3d map of the galaxy (Score:4, Interesting)
2) Once we know the diameter of Earth's orbit, we used parallax to determine the distance to nearby stars. Parallax is a process of triangulation, where we use the earth at two extremes and the star we are looking at as the three points of a triangle. Knowing two angles and one side lets us solve for the distance to the star. But the resolution of our telescopes only lets us use this method with any accuracy for stars in our immediate vicinity.
This is where the Gaia mission [esa.int] will step in and improve things drastically.
Using distant quasars as fixed beacons, Gaia will collect paralax data to all of the brightest starts in our galaxy and for a huge number of closer stars. With this data we will be able to produce a precise 3d map of our entire galaxy. We will finally be able to see it as a distant observer will see it. It will revolutionise our knowledge of space. I personally think this is the coolest astrophysics project being developed right now.
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Thank you! This may be the single most informative post in /. history.
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The observed redshift (4.5 in this case) and the Friedmann equation [wikipedia.org].
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WAG - Wild Arsed Guess.
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The spectrum shape and afterglow over time are predicted by models. Here's one cited by the J. Grenier et al. paper on arxiv: http://www.journals.uchicago.edu/doi/abs/10.1086/518996 [uchicago.edu].
Here's the J. Grenier (the GROND leader) paper on arxiv: http://arxiv.org/abs/0902.0761 [arxiv.org]
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So is the weather, and the stock market.
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So is the weather, and the stock market.
Bad analogy. We're using these models to do something more along the lines of looking at all that standing water in somebody's backyard about three states away and saying, ah yes, it rained there last night. In other words, they're looking at something that's already happened and attempting to figure out what has already happened. I think we can do this at least reasonably well for both the weather and (to a lesser extent, I suspect) the stock market.
alternate... (Score:2, Funny)
In an alternate galaxy long long ago...
Emperor palpatine went senile, and every time they fired the death star superlaser, insisted that darth vader pull his finger.
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It's a fun idea, but practically speaking, this is just far too powerful. A handful of supernovae worth of energy could fairly easily destroy an entire solar system, so a weapon yielding OVER 9000!!! (sorry) would be severe overkill. And not the fun sort of 'why not' overkill, but the inter-solar equivalent of nuking it from orbit: for when you have to be sure nothing within several hundred light-years survives (and another few thousand ltyr are devastated).
So maybe it'd be more accurate to think of these
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Alien industrial accident (Score:2)
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The 9000 figure is assuming that the radiation is spread equally in every direction. A "stellar dog fight" weapon might not work that way. Think of a laser. Focus a lot of energy into a fairly tight beam. It would look a hell of a lot more powerful if someone assumed that same amount of energy was being spread in every direction.
Power of Gamma Ray Bursts (Score:5, Informative)
My favorite comparison to illustrate the power of Gamma Ray Bursts: A Gamma Ray Burst puts out the same amount of power (while it is bursting) as all the stars in the universe together.
(Usually comparisons made in the media are rather lame, i.e. Libraries of Congress, but this one really impressed me)
Alien Hulk Incoming (Score:2)
Bah, all that star talk mumbo-jumbo. We all know what really happened.
A bunch of aliens just created the Hulk.
Kaboom (Score:5, Funny)
question (Score:3, Funny)
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Their unique properties deflect only mind control rays.
Everyone knows that.
To deflect gamma rays, you really need these magnetic bracelets! Only 19.99! They use the power of magnets to deflect the bad stuff in your body!
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Let me be the first to say.. (Score:2, Interesting)
..why is this not moderated over9000 (yet)? ;)
Yah, yah, it's old, but hey. It fits :)
Kai Hansen commented the news as (Score:3, Funny)
"awesome!"
nice summary (Score:2)
all i can think is
<keanu reeves voice>whoa</keanu reeves voice>
We have witnessed the death of several evolved (Score:3, Interesting)
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I wish I had mod points for this, so true.
They say if a supernova (does its thing) in (apparently very far distance) from earth, we'll all be wiped out.
But again, we're in the urban sprawl of the milky way,
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Since the explosion was 12.2 billion light years away, and the age of the universe is 13.7 billion years, the objects around it would have got a maximum 1.5 billion years to nurture.
Now, considering the fact that the universe was very violent at that time, there might not have been any possibility of any civilization at all.
Also considering the fact that after sun came into being, life (basic proto microbial) took almost 1.5 billion years, and from there almost 2.5 billion years to reach the current stage,
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Big Bangs... (Score:1)
They are Big Bangs "leaking" into our universe from another.
Like the one the bore our universe.
Betcha'.
That was no collapsing star... (Score:1)
I was just changing my shirt.
Total Recall, Chapter 25 (Score:2)
She stopped at a news station. "...results of the special election will be announced as they occur," the announcer said. "Meanwhile on the science front: astronomers report another `inexplicable nova' discovered. That makes seven so far. According to scientists, these novas shouldn't be happening, because they aren't the right type of stars. They--"
Something connected in Quaid's mind. "Oh, my God!" he breathed.
Melina looked at him again. "Something wrong?"
"That news item--those novas--I just realized--" He
Pass me the Sunscreen... (Score:1)
can someone pass me the SPF9000000000+ sunscreen please.
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Uh, what? Last I checked, there's only one speed that gamma rays can go in a given medium - the speed of light. Are you perhaps referring to frequency differences?
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The "speed" is how long the burst lasts for - not how fast the gamma rays go!
It's called "EIRP" (Score:3, Informative)
A common acronym you'll find in engineering and physics texts is EIRP, which stands for equivalent isotropic radiated power. This means you take the direction with the highest intensity of radiation and calculate what would be the total power if it was radiated with equal intensity in all directions.
This system of calculation is very convenient in communications engineering, because you buy amplifiers and antennas separately. Antennas which emit tighter beams are called "high gain", because using one such a
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Part Two: Decibels for Dummies - how to add gain, loss, and EIRP figures.
EIRP is typically measured in Decibels referenced to a standard power level. Decibels are a logarithmic scale that is used to compare different power or voltage levels. For power levels, the decibel ratio is 10 * log (p/p0), where p0 is the reference power. For instance, if I have a 2 Watt transmitter, its power output is approximately 3dBW (decibels referred to 1 Watt), or 33 dBm (decibels referred to 1 mW).
Antenna gain and cable los