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Supernova in M82

  1. Jan 22, 2014 #1

    Integral

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    A Super nova is just getting warmed up in M82. Note for you astrophotographers, they are looking for any recent photos of this piece of sky .
     
    Last edited: Jan 22, 2014
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  3. Jan 22, 2014 #2

    Drakkith

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    Nice. Just wish we'd see a supernova here in the Milky Way.
     
  4. Jan 22, 2014 #3

    turbo

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    But not too close.
     
  5. Jan 22, 2014 #4

    mfb

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    We had bad luck in that respect. They are expected with a rate of 2-3 per century, and the last visible one was 1604 (but astronomers found more recent remnants). Three years before the first telescope was built...
    Anyway, even if dust could block our view, the neutrino detectors will certainly note the next one.
     
  6. Jan 22, 2014 #5

    Chronos

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    Fortunately, supernova candidates in our locality are quite rare. The nearest known potential progenitor is IK Pegasus at around 150 light years. It is suspected it will probably meet its demise as a type Ia supernova. It is retreating so by the time it pulls the plug it will be even more remote from earth. A type Ia supernova could possibly adversely affect earth as far out as about 100 light years, so it looks like we are pretty safe.
     
  7. Jan 22, 2014 #6

    Vanadium 50

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    I keep hearing that number, and find it hard to believe. OK, so we can only see 15% of our galaxy. How many SN have we seen in M31 since 1800? That would be one, in 1885. How many in M33 in the same period? That would be zero. And it's not like I am cheating and picking ellipticals.
     
  8. Jan 23, 2014 #7
  9. Jan 23, 2014 #8

    adjacent

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    I would like to see a supernova as bright as the Crab nova
     
  10. Jan 23, 2014 #9

    Vanadium 50

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    I agree they have low SN rates. That's the implication from not seeing many. The question is why in light of this we think our own galaxy has SN rates an order of magnitude higher.
     
  11. Jan 23, 2014 #10

    mfb

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    Looks like the estimate comes from galaxies that are similar to ours.
    http://www.nasa.gov/home/hqnews/2008/may/HQ_08126_Chandra_Supernova.html

    We had one in 1603, there are known remnants from one in ~1680 and one in ~1870. As we certainly don't know all of them, a rate of at least 1/(200 years) looks reasonable, and 2-3 per century are possible. We can be sure no supernova in our galaxy happened in the last 20 years, as neutrino detectors would not miss that.

    All times are "as seen on earth", of course.
     
  12. Jan 24, 2014 #11
    There are several competing methods that all give a similar rate.

    Here ( http://xxx.lanl.gov/ftp/astro-ph/papers/0601/0601015.pdf ) is one recent paper using the INTEGRAL satellite.
     
  13. Jan 25, 2014 #12
    I believe that the Supernova is in the Cigar Galaxy M82 NGC3034 in UMa at around RA=135.93 and DEC=69.68 if I am not mistaken.
     
  14. Jan 25, 2014 #13

    Vanadium 50

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    Thanks for the link: note that what they call the best estimate is 67 years (and theirs is 53 years).
     
  15. Jan 26, 2014 #14

    davenn

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  16. Jan 26, 2014 #15

    Bandersnatch

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    When's the expected peak in brigthenss? My binoculars are itching.
     
  17. Jan 26, 2014 #16
    Coordinates: R.A. = 09 55 42.15, Decl.= +69 40 25.8 (2000.0)
    PSN J09554214+6940260 is offset 54" west, 21" south from the nucleus of M82

    Source: http://www.aavso.org/aavso-alert-notice-495
     
  18. Jan 26, 2014 #17

    Drakkith

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    I think they have a cream for that. :tongue:
     
  19. Jan 27, 2014 #18
    Sorry Dave and |GLITCH|. RA and DEC are in decimal degrees there. I use degrees in my calculations and I forgot to convert it back.

    This is at J2000. The position at 1-1-2000 at Greenwich 12 Midnight.

    Do not confuse it with its companion galaxy M81 also in Ursa Major: Bode's Galaxy, NGC3031.
     
    Last edited: Jan 27, 2014
  20. Feb 4, 2014 #19
    According to the spectra for SN2014J at +3 days, it shows strong Silicon II absorption line at 607 nm.

    [​IMG]

    At rest, the Silicon II absorption line should be 635.5 nm. Which would mean the spectra is blue-shifted by 4.48% the speed of light. Which would put the speed of the ejecta at ~13,445 km/s.

    That would seem to rule out the possibility of SN2014J being a Type Iax SNe, which all have ejecta traveling less than 8,000 km/s.
     
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