2 responses to “Jupiter vs. Comet P/2011 P1: No Contest”

  1. Kevin Heider

    Minor correction:
    P/ for a periodic comet (defined to have a revolution period of less than 200 years or confirmed observations at more than one perihelion passage)

    Example: http://en.wikipedia.org/wiki/153P/Ikeya-Zhang

    — Kevin Heider

  2. Gareth Williams

    This is the old way (pre-1995 designation system) of assigning periodic
    comet status. The old 200 year limit was quite arbitrary, being somewhat
    longer than the longest known (at the time) periodicity, 155-ish years for
    what is know known as 35P/Herschel-Rigollet. In the current scheme,
    the dividing line for assigning C/ or P/ is the afore-mentioned 30 years.
    See any of the recent editions of the Catalogue of Cometary Orbits, where
    comets with periods from 30 to 200 years are listed as “Intermediate Period
    Comets” and labeled C/. The assignment of P/ numbers is done without
    regard to the orbital period: the main requirement is that the object has
    been seen at two returns (the Centaur comets are handled differently,
    before someone tries to point that out…). The article is correct as written.

Leave a Reply