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Thread: A Supernova Explosion May Be Imminent

  1. #1
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    A Supernova Explosion May Be Imminent

    Two blasts, called X-ray flashes, occurred on September 12 and 16. These were followed by a more powerful burst on September 24 that seems to be on the cusp between an X-ray flash and a full-fledged gamma-ray burst. NASA indicates that these markers may warn of an imminent supernova explosion.

    http://www.gsfc.nasa.gov/topstory/2004/0930grb.html

  2. #2
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    Maybe this will get a test?
    At night the stars put on a show for free (Carole King)

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  3. #3
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    how close is this to the earth

    is it in our galaxy or within another galaxy they see

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    It is probably too soon to tell.

    One of the first indications that will point to a nearby supernova event will be the intensity of the neutrino burst rate. On February 23, 1987, a distant Type II supernova was detected in the Large Megellanic Cloud, 160,000 light years from Earth. A deep mine neutrino detection facility, Kamiokande in Japan detected 11 neutrino events. At the same time a similar facility at the Morton-Thiokol salt mine in Ohio detected 8 neutrino events. The neutrino burst occurred 18 hours before the first optical sighting of the supernova. A close supernova will produce tens of thousands of neutrino events.

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    yes but what effect would it have on us on earth , how long would it take to reach us..Would it be dangerous for us in any way like i mean life wise and stuff

    What I am trying to say is this a threat to our planet

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    Quote Originally Posted by bmpbmp
    yes but what effect would it have on us on earth , how long would it take to reach us..Would it be dangerous for us in any way like i mean life wise and stuff

    What I am trying to say is this a threat to our planet
    I found this....
    ...The empirical redshift indicator ("pseudo-z"; Atteia 2003) for GRB 040924 is 0.5.
    From.... here

    If that means an approximation of it's observerd redshift, then it was about 5 billion lyrs. from us. Hopefully, someone more knowledgeable will confirm or correct this.
    We know time flies, we just can't see its wings.

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    They achieved great response time....(per original post link)

    In addition to all of this, GRB040924 goes on record as generating the fastest response ever for a gamma-ray burst satellite. HETE-2 detected the burst and relayed information through the NASA-operated Gamma-ray Burst Coordinates Network in under 14 seconds, which led to an optical detection about 15 minutes later with the Palomar 60-inch telescope, just north of San Diego. Dr. Derek Fox of Caltech was the lead on this observation
    We know time flies, we just can't see its wings.

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    I dont understand what you mean by

    ...The empirical redshift indicator ("pseudo-z"; Atteia 2003) for GRB 040924 is 0.5.

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    Quote Originally Posted by bmpbmp
    I dont understand what you mean by

    ...The empirical redshift indicator ("pseudo-z"; Atteia 2003) for GRB 040924 is 0.5.
    Redshift is an indication of distance; 0.5 means that it's quite a long ways away (as in not even in the local galactic cluster, whose redshift is 0 for all practical purposes). A supernova would have to be in our galaxy within a hundred light years or so to be dangerous to us.
    Everything I need to know I learned through Googling.

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    So what you are saying is this one is further than a hundred light years from us and it posses no danger to us.

    Am I right on this

    Why all the commotion from scientists on this then

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    Quote Originally Posted by bmpbmp
    So what you are saying is this one is further than a hundred light years from us and it posses no danger to us.

    Am I right on this
    Yep.
    Quote Originally Posted by bmpbmp
    Why all the commotion from scientists on this then
    I don't think it's commotion. I think it's joy, it's the new toy to play with.
    At night the stars put on a show for free (Carole King)

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  12. #12
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    Quote Originally Posted by bmpbmp
    So what you are saying is this one is further than a hundred light years from us and it posses no danger to us.

    Am I right on this

    Why all the commotion from scientists on this then
    Because supernovas are rare, and this indication that one (or more) is coming may allow scientists to catch one at the earliest possible stage. Supernovas are generally not noticed until they've already flared for hours or days.
    Everything I need to know I learned through Googling.

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    Ok I get it so this one here they are mentioning is way to far off from us in order for us to worry or think twice about

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    bmpbmp, I would be more worried about getting hit by a bus walking down the street than anyhting dangerous happening beyond our atmosphere. I know there are a lot of woo woos out there who like to make everthing sound scary, but it's really not. it's beautiful out there.

    You are posting and reading on an astronomy bulletain board. of course people are going to be excited and talking about a supernova. but not because it's dangerous, but because it's cool!!

    Alos, trust me...if there was a danger from some supernova, or asteroid, or comet, you would be reading all aobut it here, and no one would be trying to cover it up.

    but back on topic...anyone know if this would be visable to us here on earth with crappy scopes?

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    I would be more worried about getting hit by a bus walking down the street than anyhting dangerous happening beyond our atmosphere.I would be more worried about getting hit by a bus walking down the street than anyhting dangerous happening beyond our atmosphere.
    I would be more worried about getting hit by an oil tanker while sitting at home (300 Km from the coast)!

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    An excellent point. =D>

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    OK, I looked but can't find it. Is this even in our galaxy? Scientists have been monitoring supernovae in other galaxies for a while. There are about 1 per galaxy per 100 years, which means they are fairly regular considering how many galaxies are out there.

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    bmpbmp, assuming my prior post reference is correct with a "pseudo z" of .5, that puts it about 5 billion lightyears away. That means if you put about 50,000 Milky Way galaxies side by side, this GRB would be radiating from the last one on the end! So, your are safe by 49,999 Milky Way diameters.
    We know time flies, we just can't see its wings.

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    Quote Originally Posted by AstroCreep
    but back on topic...anyone know if this would be visable to us here on earth with crappy scopes?
    It should be, unless it is through the "zone of avoidance" (Milky way disc). We (amateur astronomers) were able to view a recent SN in NGC 2403, not reason to think we shouldn't see this one.

    With all the fuss about detection, I'd think it was closer since we didn't get this news before the NGC2403 event.

    and yeah, it's cool!

    cheers,
    Robbo

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    are you saying it is closer than it said in the text fil 0.5

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    Quote Originally Posted by bmpbmp
    are you saying it is closer than it said in the text fil 0.5
    I think he's just speculating. Anyhow, NGC 2403 is about 5 million light years away - still a safe distance with room to spare.
    Everything I need to know I learned through Googling.

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    Quote Originally Posted by bmpbmp
    are you saying it is closer than it said in the text fil 0.5
    Not necessarily. I got the impression that the result quoted was perliminary. I (personally) expect that it would be closer. (Not dangerous, just closer).

    Later posts in the thread from AAVSO don't confirm (or deny) the preliminary redshift.

    So I think it is still up in the air.

    cheers,
    Robbo

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    Rest free, bmpbmp, and enjoy the news. It is harmless.
    We know time flies, we just can't see its wings.

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    So it sounds like you all are saying not in the Milky Way. Might it only be visible then with a good telescope?

    And Bmpbmp, if it were going to hit the Earth, we have been hit long ago. These things are occurring all the time. One per galaxy per hundred years is a lot of supernovae.

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    CNN Article posts the distances

    http://edition.cnn.com/2004/TECH/spa...eut/index.html

    The explosions occurred in the constellations Aquarius, Pisces and Aries, and all are more than 1 billion light-years from Earth, and also far away from each other, said George Ricker of the Massachusetts Institute of Technology, whose team detected the explosions with NASA's High-Energy Transient Explorer (HETE-2) satellite.

    The two in Aquarius and Pisces were the less powerful X-ray flashes, and may range from 1 billion to 3 billion light-years' distance from Earth, Ricker said in a telephone interview. The gamma ray burst was located in Aries could range from 1 billion to 8 billion light-years distance, he said.
    So if they are all more than 1 billion light years away I guess that is to far to worry right.

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    That's what? 300 Mpc? Yeah, I wouldn't be worrying about that one. SN1987A was far, far, far closer (1 or 2 dozen kpc, maybe?) I'm still fine.

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    OK, guess I'll have to answer my own question.

    09/07/04
    The closest and brightest supernova in over a decade was recorded just over a month ago in the outskirts of nearby galaxy NGC 2403. Officially tagged SN 2004dj, the Type IIP explosion likely annihilated most of a blue supergiant star as central fusion could no longer hold it up. The supernova can be seen as the bright object in the above image in the direction of the arrow. The home galaxy to the supernova, spiral galaxy NGC 2403, is located only 11 million light years away and is visible with binoculars toward the northern constellation of Camelopardalis (the Giraffe). The supernova is fading but still visible with a telescope, once peaking at just brighter than magnitude 12. Supernovas of this type change brightness in a predictable way and may be searched for in the distant universe as distance indicators.
    So now at least I have some scale to go on here. You know, for those of us who don't have the numbers in our heads.

    BTW, BA -- I tried to find something telling me about distance and scale of the Universe on your pages but couldn't. Where should I have looked?

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    I might be shot down as being wrong here, but to my knowledge, none of the stars that we know could go Super Nova would threaten Earth overly if one actually does.

    The closest is Betelgeuse, or Alpha Orionis, and that is around 400 ly away so......

  29. #29
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    Quote Originally Posted by PhantomWolf
    I might be shot down as being wrong here, but to my knowledge, none of the stars that we know could go Super Nova would threaten Earth overly if one actually does.

    The closest is Betelgeuse, or Alpha Orionis, and that is around 400 ly away so......
    I agree but just for fun, (bmpbmp, don't even read this, it isn't a problem),...

    Hypothetical star A exploded in a supernova event. Forget all the gamma ray bursts and Xrays for the moment.

    The light from star A's supernova event heads to Earth. The particles from the explosion travel behind.

    So, when the light arrives, how far behind it would the main cloud of particles be?

    And, do the particles lose momentum or not? How many things do they run into as they travel along? Would the particles that didn't hit anything not lose momentum?

    (And for the next one, bmpbmp, don't even ask if you should worry, because you shouldn't. Any distant remnant would be spread so thin by the time it arrived as to pose no problem.)

    Could there be supernova remnants headed our way that the light had already passed so we would not have any visible light from which to detect the past event?

    Thinking about my own questions, I guess the particles would be waaaay behind the light since we see remnants still around the exploded star at quite a distance years after the light from the initial event has passed.

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    They say about two weeks. We've gone over that from the first two, how much longer should we wait?
    And if Alpha Orionis flashes neutrinos and X-Rays, should I get a tad nervous?

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