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The star Betelgeuse going supernova soon?

  1. May 24, 2010 #1
    I saw this on another site.

    The star Betelgeuse going supernova soon?

    I was talking to my son last week (he works on Mauna Kea), and he mentioned some new observations (that will no doubt get published eventually) of "Beetlejuice"; it's no longer round. This is a huge star, and when it goes, it will be at least as bright as that 1054 supernova...except that this one is 520 light years away, not 6,300:

    SN 1054 (Crab Supernova) was a supernova that was widely seen on Earth in the year 1054. It was recorded by Chinese, Japanese, Native Americans, and Persian/Arab astronomers as being bright enough to see in daylight for 23 days and was visible in the night sky for 653 days.[1][2][3] The progenitor star was located in the Milky Way galaxy at a distance of 6,300 light years and exploded as a core-collapse supernova.

    http://en.wikipedia.org/wiki/SN_1054" [Broken]

    When it collapses, it will be at least as bright as the full moon, and maybe as bright as the sun. For six weeks. So the really lucky folks (for whom Betelgeuse is only visible at night) will get 24 hour days, everybody else will get at least some time with two suns in the sky. The extra hour of light from daylight savings time won't burn the crops, but this might. Probably, all we'll get is visible light (not gamma rays or X-rays), so it shouldn't be an ELE. It's sure gonna freak everyone out, though.....

    Then it will form a black hole, but we're too far away for that to matter.

    The buzz is that this is weeks/months away, not the "any time in the next thousand years" that's in all the books.

    For your reading pleasure (and I left out the tinfoil, but a google search will turn up plenty):

    Betelgeuse is a semiregular variable star located approximately 640 light-years from the Earth[5] With an apparent magnitude ranging between 0.3 and 1.2, it is the ninth brightest star in the night sky. Although Betelgeuse has the Bayer designation Alpha Orionis (α Orionis / α Ori), it is most often the second brightest star in the constellation Orion behind α; Rigel (Beta Orionis) is usually brighter (Betelgeuse is a variable star and is on occasion brighter than Rigel). The star marks the upper right vertex of the Winter Triangle and center of the Winter Hexagon.

    Betelgeuse is a red supergiant, and one of the largest and most luminous stars known. For comparison, if the star were at the center of our solar system its surface might extend out to between the orbits of Mars and Jupiter, wholly engulfing Mercury, Venus, the Earth and Mars. The angular diameter of Betelgeuse was first measured in 1920–1921 by Albert Abraham Michelson and Francis G. Pease using the 100 inch (2.5 m) John D. Hooker astronomical interferometer telescope atop Mount Wilson Observatory.

    Astronomers believe Betelgeuse is only a few million years old, but has evolved rapidly because of its high mass.[7] Due to its age, Betelgeuse may supernova within the next millennium (because it is hundreds of light years away, it possibly may have done so already).

    http://en.wikipedia.org/wiki/Betelgeuse" [Broken]

    http://www.solstation.com/x-objects/betelgeuse.htm" [Broken]

    http://domeofthesky.com/clicks/betelgeuse.html"

    http://earthsky.org/brightest-stars/betelgeuse-will-explode-someday"

    http://scienceray.com/astronomy/apocalypse-soon-supernova-betelgeuse-is-coming/" [Broken]
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. May 24, 2010 #2
    Poor Orion is gonna lose his shoulder if that is true. Pity we won't live to see.

    I think I've been watching about this in some program, the irony was that Orion - the hunter, the archer - may actually fire upon is ;)
     
  4. May 24, 2010 #3
    Ah yes, I would love to be around when this does go Supernova. I imagine it will be quite a spectacle - I'm sure it will also be a worldwide event (If religion is still going by the time it goes boom) for astronomical / Spiritual events going on.
     
  5. May 24, 2010 #4
    Hopefully it won't be going ;) A thousand years is plenty of time for people to grow beyond stupidity and dependence
     
  6. May 24, 2010 #5
    Now that's a good quote.
     
  7. May 24, 2010 #6

    Borek

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    Somehow 4000 years were not enough.

    But we better stick to astronomy.

    I don't like the idea of supernova that close. If the estimate of the Betelgeuse becoming bright as Sun is close to reality, that means huge increase in the amount of energy delivered to the Earth surface; I am sure weather will play some dirty tricks on us.
     
  8. May 24, 2010 #7
    Could it knock out power and satellites at all? Just lucky we will all be dead!!

    Once it went Supernova, it would take 3-400 years to reach us? Is this correct?
     
  9. May 24, 2010 #8

    Borek

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    According to wikipedia it is 640 ly from us, so it will take 640 years to reach us. BUT - could be it already exploded 639 years, 11 months on 29 days ago, we just don't know yet.
     
  10. May 24, 2010 #9
    Would there not be a way to see the Star in it's current form, without waiting for it's light to reach us? Or do we simply just have to wait...

    Let's say it has gone Supernova, and it hits tomorrow, would we know? Would it act like a huge EMP on a global scale?
     
  11. May 24, 2010 #10
    Yes, but we didn't have a global information network the last 4000 years, nor all the archeological findings which were revealed the last 100 years :) Those are much needed tools for that purpose, but it is unrelated to this forum...

    The orientation of Betelgeuse does not pose a risk of a gamma outburst in our direction, the only thing we have to worry is the much slower shock wave of highly charged particles that is moving a lot slower than light. It will take many thousands of years after the observable supernova before it hits us, we'd be either way more advanced or would have destroyed ourselves by then, so little worries there :)
     
    Last edited: May 24, 2010
  12. May 24, 2010 #11

    mgb_phys

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    It's neutrino's would reach us first, but not by very long - and we don't have good neutrino telescopes.
    A supernova wouldn't be that damaging at 600lyr - unlike a GRB.
     
  13. May 24, 2010 #12

    Borek

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    We have to wait. EMP is nothing else but a burst of electromagnetic radiation, and as such it travels at the same speed all types of electromagnetic radiation do - that is, speed of light.
     
  14. May 24, 2010 #13
    Thanks for that.

    Just one question, what is a GRB?
     
  15. May 24, 2010 #14
    gamma ray burst - check my previous post
     
  16. May 24, 2010 #15
    Ah yes, sorry, missed that.

    So what causes the GRB??
     
  17. May 24, 2010 #16
  18. May 24, 2010 #17
    So why wouldn't betelgeuse send out a GRB?
     
  19. May 24, 2010 #18

    Borek

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    Just note that neutrinos are earlier not because they travel faster, but because they are produced at the earlier stage of the explosion.

    Unless I am wrong.
     
  20. May 24, 2010 #19

    Borek

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    Note that GRB is narrow - that means it is emitted in one direction. It doesn't have to shine on everything.
     
  21. May 24, 2010 #20
    It could go tomorrow or in a million years. I wouldn't hold your breath.
     
  22. May 24, 2010 #21

    mgb_phys

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    They also get out of the surrounding envelope faster because they don't get scattered.

    Betelgeuse isn't massive enough to form a GRB (hopefully)
    However it's disappearance will have the effect of making my PhD thesis (IR interferometer imaging of Betelguese) even more irrelevant than it currently is.
     
  23. May 24, 2010 #22
    Lol!
     
  24. May 29, 2010 #23
    I hope it waits till next fall or we may miss the spectacular show like the Crab Nebula must have been barring an extra-large x-ray radiation event. I hope we see it happen then are safely behind the sun when the Gamma ray burst occurs.
     
    Last edited: May 29, 2010
  25. May 30, 2010 #24

    Borek

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    It ain't gonna happen. The only situation Sun can screen us is when the object is exactly in the Earth orbit plane - Betelgeuse is above. And even then we can be behind Sun only for about 12 hours - that is, Sun lies between us and any other distant object for only about 0.15% of the time. We would need a lot of luck.
     
  26. May 30, 2010 #25
    I've been looking a little at this myself lately. The original source, unfortunately, is not verifiable. However, it's basically not inconsistent with existing observations of Betelgeuse, which indicate that after a long period of fluctuation in size with a period on the order of several years, it has been shrinking continuously (and at an increasing rate) since 1993. If this does reflect a permanent change in the internal state of the star and Betelgeuse has entered its final collapse, we would expect it to become progressively more non-spherical as it collapses. I imagine I don't need to point out that the brightness estimates in the initial article are WAY off, though.

    The original post uses SN1054 as a reference. Let's do that. And let's also look at SN1006, although SN1006 was probably a Type 1a supernova. SN1054, at a distance estimated at 6300LY, is estimated based on accounts written at the time to have reached apparent magnitude -6. SN1006, the brightest extra-solar stellar event ever observed and recorded by humans, reached absolute magnitude -7.5 from a distance estimated at 7200LY. Measurements of Betelgeuse's distance vary from 495LY to about 620LY, with the "best compromise" estimates considered to lie between 530LY and 570LY.

    To start with, if we assume Betelgeuse would be like a SN1054 event, we can predict that simply by virtue of being between 11 and 12 times closer, a Type II supernova of Betelgeuse would appear somewhere in the region of 130 to 140 times brighter than SN1054 merely by virtue of being closer. This would mean an apparent magnitude somewhere around -12, making it a little less than half as bright as the full moon (magnitude -12.92).

    This, however, assumes that Betelgeuse is just like the progenitor star of SN1054, which it is not. We believe that SN1054's progenitor star was between 9 and 11 solar masses. This is about half the mass of Betelgeuse, estimated at 20 solar masses. We can therefore expect Betelgeuse's supernova to be a considerably more energetic event than SN1054, but we don't know by how much. So let's also compare to SN1006, which was a full 1.5 magnitudes brighter than SN1054 despite being almost 1000LY further away. We can readily calculate that SN1006 had to have an absolute luminosity on the order of 5.2 times that of SN1054. This is a little under two magnitudes.

    So, if we assume that a Type II supernova of Betelgeuse would be at least as luminous as SN1054 (a not unreasonable assumption), but no more luminous than SN1006, we can ballpark its probable apparent magnitude at somewhere in the range of -12 to -14, or, in other words, from roughly half to roughly twice the maximum brightness of the full moon. (Remember, though, to visual observation it will be a point source. It will be piercingly brilliant.) But there is no way it's going to be 12 to 13 magnitudes (absolute) brighter than SN1006, which is what it would take to rival the Sun.

    So, as bright as the full moon? Very likely. As bright as the sun? Not a chance, unless something far more catastrophic happens than our understanding of stellar evolution would currently lead us to expect.
     
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