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UPDATE ON 107P=4015: GOOD NEWS, BAD NEWS

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  • iferrinv
    Situation up to 091129 The secular light curve up to 091129 is shown in my webpage: http://webdelprofesor.ula.ve/ciencias/ferrin We have good news and we have
    Message 1 of 2 , Dec 1, 2009
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      Situation up to 091129
      The secular light curve up to 091129 is shown in my webpage:

      http://webdelprofesor.ula.ve/ciencias/ferrin

      We have good news and we have bad news.
      The good news is that the activity is well defined.
      The bad news is that the activity seems to be fading away.
      So the comet may be inactive in about 10 days, or December
      9th, *approximately*.

      We can sum up the circumstances of this apparition
      in a *very very* preliminary way, thus:

      Turn on point = ~ +23 d after perihelion
      Turn off point = ~ +47 d after perihelion
      Time active = ~24 days
      Amplitude of the activity = ~0.7 magnitudes

      It is then possible to determine the Time-AGE defined in
      the Atlas, which is a measure of age. The formula is:

      T-AGE = 90240 / [ Asec . Tactive ] comet years

      T-AGE = 5400 comet years (!)

      Notice that in the Atlas 95% of the comets listed have
      T-AGE < 100 cy. Thus this comet is an exceedingly
      old object, in fact a methuselah comet of great interest.
      At the present moment holds the record as the oldest
      comet in our data base.
      Observations should continue to see when it turns
      off.
      Good luck.
      Kind regards,

      Ignacio Ferrin
      Center for Fundamental Physics,
      University of the Andes,
      Merida, Venezuela
      ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    • David Seargent
      Hi Ignacio, This is truly a very interesting object. I once read that observations during its 1979 re-discovery apparition found the colour of the object to be
      Message 2 of 2 , Dec 1, 2009
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        Hi Ignacio,

        This is truly a very interesting object. I once read that observations during its 1979 re-discovery apparition found the colour of the object to be a close match to the CK meteorite Karoonda, which fell in South Australia in 1930, and this set me wondering as to whether there might be some connection between the two objects. Karoonda is a very rare type of meteorite; in fact, at the time it was the only CK known. Some more have since been found in Antarctica and similar regions, but the only other seen to fall was in (I think from memory) 1999! Also, the spectral type given to 107P was CF, which also seems rather unusual for a near-Earth object.
        I searched for all the information that I could find on Karoonda, but unfortunately this didn't amount to much! Nevertheless, from the few descriptions available, I tried to derive an orbit using a programme written by Rob McNaught with the following results;

        T = 1930, Dec. 6.3
        e = 0.72814
        q = 0.97397
        semi-major axis = 3.58261
        w = 14.391
        W = 62.802
        i = 3.492
        P = 6.781 years

        I am certainly no expert in meteorite orbits and, at best, these values can only be approximate. In particular, e seems rather high. In any case, the orbit is nothing like that of 107P, but I was wondering if the comet's orbit in the distant past may have been closer to the meteorite's.
        Any thoughts?

        Regards,
        David Seargent








        ----- Original Message -----
        From: iferrinv
        To: comets-ml@yahoogroups.com
        Sent: Wednesday, December 02, 2009 8:43 AM
        Subject: [comets-ml] UPDATE ON 107P=4015: GOOD NEWS, BAD NEWS


        Situation up to 091129
        The secular light curve up to 091129 is shown in my webpage:

        http://webdelprofesor.ula.ve/ciencias/ferrin

        We have good news and we have bad news.
        The good news is that the activity is well defined.
        The bad news is that the activity seems to be fading away.
        So the comet may be inactive in about 10 days, or December
        9th, *approximately*.

        We can sum up the circumstances of this apparition
        in a *very very* preliminary way, thus:

        Turn on point = ~ +23 d after perihelion
        Turn off point = ~ +47 d after perihelion
        Time active = ~24 days
        Amplitude of the activity = ~0.7 magnitudes

        It is then possible to determine the Time-AGE defined in
        the Atlas, which is a measure of age. The formula is:

        T-AGE = 90240 / [ Asec . Tactive ] comet years

        T-AGE = 5400 comet years (!)

        Notice that in the Atlas 95% of the comets listed have
        T-AGE < 100 cy. Thus this comet is an exceedingly
        old object, in fact a methuselah comet of great interest.
        At the present moment holds the record as the oldest
        comet in our data base.
        Observations should continue to see when it turns
        off.
        Good luck.
        Kind regards,

        Ignacio Ferrin
        Center for Fundamental Physics,
        University of the Andes,
        Merida, Venezuela
        ++++++++++++++++++++++++++++++++++++++++++++++++++++++++





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