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If Betelgeuse Went Supernova Soon

  1. Mar 26, 2012 #1

    Drakkith

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    Hey guys. Just wanted your thoughts on this.
    If Betelgeuse went supernova soon, like in the next few years, how helpful to our understanding of supernovae would it be? Given it's short distance and ability to directly see the surface of the star, would this be like the "holy grail" of type 2 supernova study?
     
  2. jcsd
  3. Mar 26, 2012 #2
    I want it to be soon, if it will not harm our earth
     
  4. Mar 26, 2012 #3

    Chronos

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    Earth is safe. Type II supernova are only potentially hazardous if within about 30 light years. Betelgeuse 600 light years distant.
     
  5. Mar 27, 2012 #4
    I read somewhere tha it has potential to become neutron star, what if it will?
     
  6. Mar 27, 2012 #5

    MathematicalPhysicist

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    I wonder why we don't have such a supernova closer in withing 30 ly.
    :devil::tongue:
     
  7. Mar 27, 2012 #6

    Chronos

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    Any star more than about 8 solar masses is a core collapse supernova candidate - which is basically the mechansim necessary to generate a neutron star. Fortunately, no stars in the 8+ solar mass range are located anywhere near earth. Sirius A is probably our most massive nearby star and weighs in at just over 2 solar masses. So, earth appears does not appear to be at risk of being ravaged by a core collapse supernova.
     
  8. Mar 27, 2012 #7

    MathematicalPhysicist

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    What a nice coincidence...:-)
     
  9. Mar 27, 2012 #8
    Then i pray to expload in a next second
     
  10. Mar 27, 2012 #9
    it certainly would be a sight to behold
     
  11. Mar 27, 2012 #10
    Interesting topic Drakkith.

    Does anyone know the magnitude Betelgeuse going nova would be?

    Just wondering how visible this would be during the day and at night - I suspect it would light up the night sky and be clearly visible through the day but would be interested in the numbers.
     
  12. Mar 27, 2012 #11
    I think it will be like moon light
     
  13. Mar 27, 2012 #12
    wikipedia estimates about -12 magnitude. For reference, also from wikipedia, the apparent magnitude of the full moon is -12.74... so yes, it will be quite magnificent. And since wikipedia also says it should remain at about -12 magnitude for a few months, it would be very cool to see it alongside the full moon.

    Betelgeuse_supernova.png

    from wikipedia, this is an image it says is taken from Celestia and shows Betelgeuse as it might appear from Earth if it goes supernova and someone looks at it. Although it doesn't show much of what sort of lighting it would provide on Earth... it sure does look bright, reminds me of the following picture that apparently shows the sun from Jupiter's distance, and in fact looks a bit brighter.


    SunFromJupiter.jpg
     
  14. Mar 27, 2012 #13

    Drakkith

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    Remember that while the full moon may be -12 magnitude, it's light is spread out over a half degree wide circle, whereas Betelgeuse would be a point source. It would probably be very difficult to look at directly.

    But anyways, I'm still wondering how this, or any supernova visible in our galaxy, would help our understanding of supernovas. Is there much we can gain just by being closer?
     
  15. Mar 27, 2012 #14

    Chronos

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    Supernova 1987a detonated at a 'mere' 160,000 light years and is still providing a wealth of information. It was the brightest supernova since the Kepler supernova of 1604 which is located about 13,000 light years from here. This puts the relative scarcity of core collapse supernova in perspective. It requires a very massive star and these are pretty rare creatures. These heavy weights are so luminous during their main sequence phase they are readily visible at great distances - like Betelgeuse at 600 light years.
     
  16. Mar 28, 2012 #15

    MathematicalPhysicist

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    Any prediction when the fat lady is going to explode?
     
  17. Mar 28, 2012 #16
    Who know it was already exploded in between last 600 yrs or will explode in next million yr
     
  18. Mar 28, 2012 #17

    MathematicalPhysicist

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    Obviously untill the light comes to earth plenty of years will pass, my question is according to the data we have when will this light of explosion will get to earth?
     
  19. Mar 28, 2012 #18

    Drakkith

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    It will take approximately 600 years for the light to reach Earth once Betelgeuse goes supernova. We cannot predict when it will happen to an accuracy greater than a few million years currently. Hopefully as it approaches we will see fluctuations or something that will tell us it's about to happen.
     
  20. Mar 28, 2012 #19

    phyzguy

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    I think we know more accurately than a few million years. Betelgeuse has already expanded into a red supergiant, which means it has exhausted the hydrogen in its core and moved on to the helium burning phase and possibly beyond. In a star the mass of Betelgeuse (about 20 times the mass of the sun), this phase only lasts on the order of a hundred thousand years. So it should blow within the next few hundred thousand years, possibly tomorrow.

    Yes, it's true it will take the light 600 years to reach us after it blows, but it might have blown 599 years, 364 days ago, so we could see it go off tomorrow.

    In terms of how it would increase our knowledge of supernovae, it would have a huge impact. Here are two ways. First, since we have studied Betelgeuse extensively, we know a lot about it before it goes off. There are only a few supernovae where we have information on the star before it blew - usually we only find them when they explode. So this would help a lot to refine the models of which types of stars give rise to which types of supernovae. Second, we would learn a lot about the core collapse from the neutrino emissions, which come directly from the core. For SN1987A, we measured ~25 neutrinos here on Earth when it went off. But because Betelgeuse is so much closer, and because the neutrino detectors are so much better than they were in 1987, we would measure many thousands of neutrinos. This would give us neutrino energy spectra and neutrino light curves, which would tell us a lot about the details of the explosion as the core collapses. The light we see comes from the cloud of expanding gas far outside the actual explosion, but the neutrinos 'free stream' directly out from the core collapse itself.

    I hope it (or another star in our galaxy) goes off in my lifetime. As has been said, the last one in our galaxy was in 1604, so we are 'due'.

    BTW, I have an astronomer friend who has nightmares that Betelgeuse will go off while his telescope is down for maintenance!
     
  21. Mar 28, 2012 #20

    Drakkith

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    Thanks Phyz.
     
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