[AZ-Observing] New Damocloid

     Last week, before the rains, I discovered an asteroid that showed unusual
motion.  This was announced today and the orbit shows it to be a new member
of what are colloquially called 'Damocloids', after the first such object,
(5335) Damocles.  These are asteroidal objects that have very elongated orbits
broadly similar to that of Comet Halley.  Some probably really are ex-comets
(like the ex-parrot in the Monty Python "Pet Shop" routine), but others could
be purely asteroidal objects perturbed into the inner solar system from the
vicinity of the Oort Cloud.
     The Minor Planet Electronic Circular below omits all but the discovery
observations, which were up against the winter Milky Way in the morning sky.
Because the object is relatively bright (mag. 17!), it was clobbered by the
amateurs around the world who do follow-up astrometry.  Over the last six days
they accumulated almost a hundred observations (a dozen would have been
plenty).
     It may be of interest to the list to show all the observers and their
hardware.  A few years ago a lot of amateurs were making these positional
measurements with 6- and 8-inch telescopes with CCDs.  But because the pace of
discovery has begun to include more and more objects below mag. 19, amateurs
have been forced to upgrade equipment, as is evident here (the CCDs are
upgraded, too, but that is not obvious in the details below).  The smallest
telescopes used were several 30cm (12-inch) Meade SCTs.  After one 35cm
(14-inch) Celestron Schmidt, the remaining larger telescopes are all
Newtonians, traditional Cassegrains, or Schmidt cameras, including several
active sites with 24- and 30-inch telescopes.  Two larger apertures are at
professional sites in the Czech Republic and in Canada.  Whereas five years ago
none of the amateur observers would likely to have been from the US, the list
here shows five US amateur sites.  (Several possible additional contributors
in the Southwest were of course largely clouded out the last several days.)
     The several comments indicating "stellar appearance" result from requests
by the Minor Planet Center to know whether there was any cometary activity,
since the orbit is very comet-like.  But even the 72-inch telescope showed
no activity.  This is only the sixteenth 'Damocloid' found so far, so though
less exciting than a comet, it is more rare.

\Brian

P.S.:  The full MPEC is here:  http://cfa-www.harvard.edu/mpec/K02/K02R43.html
       A list of Damocloids is here:  ftp://ftp.lowell.edu/pub/bas/damocloid



M.P.E.C. 2002-R43                                Issued 2002 Sept. 10, 23:34 UT

     The Minor Planet Electronic Circulars contain information on unusual
         minor planets and routine data on comets.  They are published
   on behalf of Commission 20 of the International Astronomical Union by the
          Minor Planet Center, Smithsonian Astrophysical Observatory,
                          Cambridge  MA 02138  U.S.A.

             Prepared using the Tamkin Foundation Computer Network

                              MPC@xxxxxxxxxxxxxxx
          URL http://cfa-www.harvard.edu/iau/mpc.html  ISSN 1523-6714

                                  2002 RP120

Observations:
    K02RC0P* C2002 09 04.41040 04 41 22.24 +09 12 32.2          16.8 R      699
    K02RC0P  C2002 09 04.42802 04 41 21.24 +09 12 44.4                      699
    K02RC0P  C2002 09 04.44560 04 41 20.22 +09 12 56.3                      699
    K02RC0P  C2002 09 04.46315 04 41 19.20 +09 13 08.3                      699

(98 observations omitted...)


Observer details:
113 Volkssternwarte Drebach, Schoenbrunn.  Observer T. Payer.
    0.5-m f/5 reflector + CCD.
118 Modra.  Observers L. Kornos, J. Toth, S. Gajdos, M. Seben.
    0.6-m f/5.5 reflector + CCD.
170 Observatorio de Begues.  Observer J. Manteca.  0.31-m f/6.3
    Schmidt-Cassegrain + CCD.
176 Observatori Astronomic de Consell.  Observers A. Lopez, R. Pacheco.  0.4-m
    f/4 reflector + CCD.
246 Klet Observatory-KLENOT.  Observers J. Ticha, M. Tichy, M. Kocer.
    1.06-m KLENOT telescope + CCD.  Stellar appearance.
557 Ondrejov.  Observers P. Pravec, P. Kusnirak.  0.65-m f/3.6 reflector + CCD.
    Stellar appearance.
595 Farra d'Isonzo.  Observer E. Pettarin.  0.30-m f/4.0 reflector + CCD.
599 Campo Imperatore-CINEOS.  Observers A. Boattini, F. Bernardi, A. Di Paola.
    0.6-m f/3 Schmidt + CCD.
649 Powell Observatory, Louisburg.  Observers K. Smalley, M. Glaze.
    0.75-m Newtonian + CCD, 0.30-m Schmidt-Cassegrain + CCD.  Stellar
    appearance.
658 National Research Council of Canada.  Observer G. B. Poole.  Measurer
    D. D. Balam.  1.82-m Plaskett telescope + CCD.  Stellar appearance.
670 Camarillo.  Observer J. E. Rogers.  0.30-m f/6.7 Helin Telescope + CCD.
671 Stony Ridge.  Observers S. C. Brewster, D. Chappell, D. Hadlen, S. Martin,
    J. E. Rogers, P. Sable.  0.76-m f/6 reflector + CCD.
699 Lowell Observatory-LONEOS.  Observer B. A. Skiff.  0.59-m
    LONEOS Schmidt + CCD.
734 Farpoint Observatory.  Observer G. Hug.  Measurer R. Valentine.  0.30-m
    Schmidt-Cassegrain + CCD.
848 Tenagra Observatory, Cottage Grove.  Observers P. R. Holvorcem,
    M. Schwartz.  Measurer P. R. Holvorcem.  0.36-m f/11 Schmidt-Cassegrain
    + CCD.
850 Cordell-Lorenz Observatory, Sewanee.  Observer D. T. Durig.  0.3-m f/5.75
    Schmidt-Cassegrain + CCD.  Stellar appearance.
941 Observatorio Pla D'Arguines.  Observer R. Ferrando.  0.30-m
    Schmidt-Cassegrain + CCD.
946 Ametlla de Mar.  Observer J. Nomen.  0.40-m f/2.0 Schmidt + CCD.
J95 Great Shefford.  Observer P. Birtwhistle.  0.3-m Schmidt-Cassegrain + CCD.

Orbital elements:
2002 RP120
Epoch 2002 Sept. 3.0 TT = JDT 2452520.5                 MPC
M 359.90174              (2000.0)            P               Q
n   0.00300896     Peri.  357.66149     +0.76206389     +0.33793560
a  47.5180356      Node    39.17519     +0.60736011     -0.66873802
e   0.9479416      Incl.  119.03198     +0.22443779     +0.66226051
P 328              H   12.4           G   0.15
From 102 observations 2002 Sept. 4-10.

Ephemeris:
2002 RP120               a,e,i = 47.52, 0.95, 119                q = 2.4737
Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase     V
2002 09 03    04 42.65   +08 56.8    2.286    2.498    89.9    23.8    17.3
2002 09 13    04 31.38   +10 55.5    2.074    2.485   101.9    23.3    17.1
2002 09 23    04 14.09   +13 12.1    1.874    2.477   115.5    21.4    16.8
2002 10 03    03 49.12   +15 45.9    1.700    2.474   130.9    17.8    16.4
2002 10 13    03 15.32   +18 26.2    1.571    2.475   148.1    12.3    16.1
2002 10 23    02 33.61   +20 48.8    1.504    2.481   165.7     5.7    15.7
2002 11 02    01 48.22   +22 24.9    1.512    2.491   167.8     4.8    15.7
2002 11 12    01 05.46   +23 04.0    1.594    2.505   150.9    11.1    16.1
2002 11 22    00 30.14   +23 02.2    1.737    2.524   133.9    16.4    16.5
2002 12 02    00 03.63   +22 44.2    1.924    2.548   118.6    19.9    16.8
2002 12 12    23 45.04   +22 28.2    2.137    2.575   105.0    21.7    17.2
2002 12 22    23 32.69   +22 23.4    2.363    2.606    93.0    22.1    17.4
2003 01 01    23 25.02   +22 33.0    2.589    2.641    82.1    21.6    17.6
2003 01 11    23 20.76   +22 57.3    2.809    2.679    72.3    20.5    17.8
2003 01 21    23 18.97   +23 35.6    3.017    2.721    63.3    18.9    17.9
2003 01 31    23 18.96   +24 26.8    3.208    2.765    55.1    17.0    18.0
2003 02 10    23 20.19   +25 30.1    3.378    2.813    47.9    15.1    18.1
2003 02 20    23 22.24   +26 44.5    3.527    2.863    41.6    13.2    18.2
2003 03 02    23 24.81   +28 09.3    3.651    2.916    36.6    11.7    18.2

Brian G. Marsden             (C) Copyright 2002 MPC           M.P.E.C. 2002-R43
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