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Furthest Gamma-Ray Burst Ever Observed
jd writes "The SWIFT team have announced the furthest-ever observed super-massive gamma-ray burst (from 13 billion light years away). The burst was observed on the 6th of September and lasted for 3 minutes - long enough for a number of other telescopes to home in on the gigantic explosion. The distance is only barely within the reaches of the observable universe. The idea of the SWIFT telescope and follow-up observations is that they will discover both the cause of the bursts and the consequences to the star."
I feel a great disturbance in the Force (which we all know travels at the speed of light). As if millions of voices suddenly cried out in terror, and were suddenly silenced.
Maybe it was the universe's first post, or the explosion caused by the first moderators giving the first post first -1.
Black holes are where God divides by 0. Gamma explosions are where God divides by 0.0000000000000000001 - God's accountant
Table-ized A.I.
Imagine there are a few people rather lost at the headline (we're not all astronomers/cosmologists/whatever :) ). Anyway, NOVA ran an excellent show on this a couple years ago, and as usual there was an excellent companion website.
/I feel like a Karma whore linking to wikipedia, mod me as you see fit..
If that doesn't answer your questions, well... there's always Wikipedia.
Wow, Slashdot really dropped the ball on this one, this news is 13 billion years old.
I'm agneglectic, too lazy to care if there is a God.
How do we know the universe is 13.7 billion years old? It was recently discovered that the universe's expansion is accelerating as time goes by. Assuming this change in acceleration has been the case all along, doesn't that really fudge with the numbers we used to estimate the universe's age?
There are many ways to estimate the age of the universe, not all of which involve calculating the expansion of the universe.
http://www.astro.ucla.edu/~wright/age.html
What?
I *think* we observed, or tried to observe, this burst from our local observatory WIRO. At its high redshift, we probably just got limits with the optical camera that was on the telescope. I'll have to check with my student Cassandra Paul who was on and targeted a burst last week. They released some kind of circular.
As a quasar guy, I'm excited about this result but happy a quasar still holds the redshift record.
Professor of Astronomy, Author of Spider Star & Star Dragon (Tor)
When supernovae occur you can see them. Are they the brightest visible object?
Galaxies are the brightest visable objects. Well, actually quasars are, but are thought to be galaxies or at least closely related to them. But the total energy put out by gamma bursts is far larger than the energy put out by supernova. It is just that they do it over a wider area of the spectrum such that their visible light component is roughly comparable to supernova but beat them by far in higher-energy radiation.
Table-ized A.I.
Well, the leading idea about (this type of) gamma ray burst says that they're associated with supernovas. So, they look like supernovas.
Quasars are the most luminous long-lived light sources. Gamma ray bursts can release more energy for short periods of time, but there are arguments about to what extent the energy is beamed in a preferred direction (complicating efforts to calculate total energy released).
I'm not sure what you mean by "alpha and beta?" Are you talking about alpha and beta radiation? Apples and oranges, although all are called "radiation". Gamma rays are a form of light (very high energy photons), while alpha and beta radiation isn't electromagnetic radiation at all, but rather particles (He nuclei and electrons).
Professor of Astronomy, Author of Spider Star & Star Dragon (Tor)
If the distant explosions are caused by aliens
Since they seem to go back to the time that the universe was only 1 billion years old, that is fairly unlikely. Stars back then were too immature to produce enough complex elements thought needed by life. It takes several birth-death cycles for stars to produce non-simple elements, such as carbon.
Further, even if they did arise that early, having the Cosmic Nuke back then would almost certainly have resulted in more noticable changes. One could argue that they blew themselves up, but gamma bursts seem fairly uniform over time and space. Weapons technology growth and use tends not to be uniform, based on earth history.
Finally, they don't seem clustered (repeating in same vacinity). Most wars produce clusters of weapon usage, near the front lines. These so far seem random.
Table-ized A.I.
For being so feisty, are you quite sure there's no such thing as alpha and beta radiation?
http://www.orau.gov/reacts/alpha.htm
http://www.orau.gov/reacts/beta.htm
Both are particle radiation and both plentifully originate in stars. You can read more about them in Wikipedia also.
http://en.wikipedia.org/wiki/Particle_radiation
ahem. Farthest Gamma-Ray... Farthest . 'Further' is a definition of degree. 'Farther' is a measure of distance.
Correct. For instance, the easiest way is to just cut the universe in half and count the rings.
For a homework problem, I have my astronomy students calculate how bright the Galactic core would be if it were a quasar and there wasn't any obscuring dust in the plane of the galaxy. It turns out to be about the brightness of the full moon, but since it would be smaller, it would be more striking. That's at a distance of 8 kpc or so.
Professor of Astronomy, Author of Spider Star & Star Dragon (Tor)
Someone or another asks something like this everytime anything related to black holes comes up on Slashdot.
The radiation emitted from black hole related events, such as quasars, gamma ray bursts, and Hawking radiation, for that matter, comes from processes near-sometimes very near, but still OUTSIDE, the event horizon. As long as you're outside the horizon, there are trajectories that escape.
As for,
Also, if a black hole was created at explosion, was this even more massive then we can see, yet the black hole swallowed up a majority of the explosion and what we see, is just a small glimpse of it?
According to the literature on very massive stars, there as mass ranges that results in the star collapsing completely into a black hole such that no significant amount of matter or radiation gets away at all.
Check out How Massive Single Stars End their Life. Figure 1 is particularly enlightening. It's a pretty math-free article, so I think anyone who's generally interested in this stuff can follow it, maybe with a bit of help from Wikipedia and Science World.
Credo sim. - I think I am.
Light is usually defined as visible light. If you start using the term light to refer to radio waves, you'll only sound very confused.
As someone else already pointed out there is such a thing as alpha and beta radiation. I'd suggest some remedial physics classes before you discuss physics with anyone again.
AccountKiller
I Am Not an Astronomer/Cosmologist
"If this massive gamma-ray burst resulted in a black hole, then how did the light escape enough to reach us here on earth,"
Only stuff inside the event horizon after a star has collapsed that far gets trapped. The bits of the implosion/explosion outside that radius gets out. Newton dictates that whatever pushes in against the core of a star to collapse it into a black hole also pushes the pusher in the opposite direction.
"I would love to see some pictures or even video of this event,"
A new pinpoint of light appears, then goes away after 3 minutes (assuming you can see gamma rays). Even the most powerful telescopes looking at Alpha Centauri only sees a pinpoint of light. They can get brighter or dimmer, but never "larger."
"Another question comes to mind, what if Earth and the entire Milky Way Galaxy itself, was actually trapped inside of a giant blackhole???"
Things closer to the center wouldn't be visible to us, because the light would be going the other way. Things farther away than us would only be visible as high-energy stuff, with other galaxies probably blue-shifted well into the gamma radiation range of the EM spectrum. Laterally, we might be able to see ourselves with powerful enough telescopes.
"yet the black hole swallowed up a majority of the explosion and what we see, is just a small glimpse of it?"
It's an all-too-big part of it. If the gamma ray burst that we saw was in our galaxy and still pointed at us, we'd be dead.
My understanding is there's a low-res, very wide angle gamma-ray detector that they can use to scan vast sections of the sky. If the computers see anything interesting, they spin the probe to get a better look. If it's still a strong candidate, it then notifies anything and everything on Earth that is interested in such events.
The problem used to be that, precisely because they had to book telescopes and because telescopes are rather unwieldy, even if they saw something, it was too late to get an accurate enough fix to see what the cause was.
SWIFT was designed to solve this problem. In fact, it has discovered far more bursts than the astronomers were expecting and it started detecting them far sooner. (They got half-drowned in notifications, during the test and burn-in phase.)
So far, it has been an outstanding success - second only to Hubble, in the sense that Hubble generates better pics for the press and the average space geek. As far as I know, SWIFT was not designed to really record much in the way of actual hard data (other than location), it was more an early-warning system for giant space explosions. That is partly how it works so fast, but with the pitfall that it means that you HAVE to have additional telescopes available, if it does detect something.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
You're thinking "hand grenade in a vacuum." There was no space-time before the Big Bang, that's what it created. We're not racing away from everything, the space-time between us is spreading out. The two-dimensional analogy used in Sphereland is that of the universe being the surface of a balloon that's being inflated.
This is why the cosmic background radiation, which is a relic from the Big Bang, is visible in all directions with the same intensity.
I am a computer engineering kid. Sexy hardware gets me hot, tight software that climbs up to a level i've not pondered is sexy to me ... or even down to a level i don't play in.
... just for a second imagine the roiling, nuclear fire that churns inside each one ... the amount of matter transformed into energy by each one, each second you watch?
.. and marvel your face off.
But i have to ask, do you ever just look at the sky at night?
Do you? Do you really sink deep into your mind the vast firestorm that goes on above your head every day and nigh? Do you look at the stars and
Do you?
Break your mind for a second and imagine the scale of this place your little planet wanders around
We've had NASA support for GRB followup at Wyoming's observatory, WIRO. We have someone on call every night who gets an alert seconds after SWIFT localizes a GRB. They in turn call the WIRO observers on that night who finish their current exposure and then point at the GRB field. When everything is working, and the right instruments are on (e.g. imagers), and the weather is clear, we can start taking data within five minutes of the GRB. It's kind of cool, especially given that the system is not robotic.
The space telescopes, in general, are much more difficult to reprogram quickly aside from the systems like SWIFT designed to detect these GRBs.
Professor of Astronomy, Author of Spider Star & Star Dragon (Tor)
Any object at the edge of the observable Universe would appear to be travelling away from us at the speed of light. Which basically means, we'd never see it. (The red-shift would be infinite, amongst other things.) That's not quite the definition of the observable Universe, but it'll do.
Anything marginally closer will be visible, but because there is an ever-increasing gap, the closer it is to the edge, the longer it'll take to see. (This is because although light travels at a fixed velocity, it is space that is expanding and therefore there is more distance to travel through.)
In fact, your question works rather better in reverse. Given the speed implied by the red-shift, can you calculate the fantastic distances that must be involved? The answer is yes, provided you can eliminate (or allow for) any unknowns.
For objects that have a well-defined spectral output and luminosity, it's easy. You simply compare what you see with what you should see. The shift in frequency and the reduction in output observed can both be used to guesstimate a distance.
For objects of an intermediate distance, it's harder. There are gravitational lenses, which can make objects appear further away. They're often not close enough to other objects to be able to measure an unknown against a known. Those tend to be tougher.
The further an object is, the less important lensing is, as you'd have to bend light more to add enough distance to be significant. By the time you get to 13 billion light-years, the lens would be so bloody obvious in its own right, you'd have probably spotted it first and allowed for it.
However, you can't verify calculations at all easily. At those sorts of distances, you're talking about phenomena that astronomers don't fully comprehend and cannot, therefore, tell what the profile would normally look like.
That is one reason it is important to get a good look with as many types of telescope as possible, so that we can see what created the gamma-bursts, or whatever. That way, we can verify our calculations.
(This is actually important - strange things can happen when you don't verify data. Superluminal motion, stars older than the Universe - all have been observed, but usually because of incorrect calculations or incorrect assumptions.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
The way we figure the distance to the furthest objects (in the 1 - 14 billion light-year range) is precisely by the rate of retreat of the astronomical objects we observe. It was noted empirically (back in the 1920's, I think) that the further away an object is from us, the faster it is retreating, in roughly linear proportion. The rate of retreat is figured out by how much the object's spectra shifts (due to the Doppler effect). So yes, some very far away objects are retreating at speeds damned near the speed of light.
5 071334/ref=lpr_g_1/103-7798844-8308625?v=glance&s= books
Originally, when Einstein came up with his field equations in General Relativity (1915?), they did not have a steady state solution; but an expanding universe WAS a possible solution. Apparently, this disturbed Einstein so much that he threw in a "fudge factor" called the cosmological constant, in just such a way that a steady state solution existed for the general configuration of the universe. Of course, as more and more observations poured in indicating that virtually ALL extra-galactic objects were retreating away from us, with higher speeds the further away, it became clear that the Universe was, in fact, expanding, despite the tastes of Einstein. He removed the mathematically ugly constant, and I think he later said that messing up his original equation with it was the "greatest mistake of my life."
Of course, you may wonder how we figured out how far some objects were to begin with to USE our distance = (constant) x speed formula. This post is getting a bit long, but it turns out that supernova, explosions of very massive stars at the end of their lives, tend to have an absolute maximum brightness that has a simple relationship to the length of time they "explode". Thus, supernovae can serve as a yardstick if we can spot them in other galaxies; and fortunately, they are bright enough so that we can - I think they are the ONLY individual stars we can discern in other galaxies; all the others are just too dim from those distances....
And how do we determine how far away the "first" supernova is? In other words, how did we calibrate that yardstick? Here I'm not sure; we haven't had a supernova go off close by (meaning, in our galaxy) in the last 500 years (and that's a GOOD thing - a supernova can shine as brightly as an entire galaxy at its peak! There was one in one of the Magellanic clouds (a pair of small, neighborhood galaxes) in 1987, I think); I know we have other yardsticks from direct parallax measurements (measuring the shift of nearer stars vs. their further cousins as the Earth shifts its position around the sun - good out to about 1000 light years now, I think), our knowledge of the absolute brightness to temperature as revealed by spectrum/color of stars on the main sequence, and some knowledge of the brightness patterns of ordinary novae...
There is a really good book called Parallax, which goes into the whole history of how we figured out how far away stuff in the Universe is - it's a fascinating, wonderful read; here is the amazon URL:
http://www.amazon.com/exec/obidos/tg/detail/-/080
Hope this helps.
I know /. is famous for old news--but come on, this is 13 Billion years old...
you have the wrong idea of "the center of the Universe". that's a meaningless phrase. We are at the center of our observable universe, but the universe as a whole is expanding, and you could call any body you wish the "center", and if you were located there you would see the rest of the universe moving away from you.