Electronic Telegram No. 2867
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET P/2010 TO20 (LINEAR-GRAUER)
     A. D. Grauer reports the discovery of a comet on CCD images obtained with
the Mount Lemmon 1.5-m reflector (discovery observation tabulated below); the
object was described in four stacked 60-s unfiltered frames as being diffuse
with a 6"-10" coma and a fan-shaped tail 20"-25" long in p.a. 250 degrees.
After posting on the Minor Planet Center's NEOCP webpage, G. Sostero writes
that observations obtained by I. Melville, A. Kasprzyk, N. Howes, E. Guido,
and himself with the 2.0-m f/10 Ritchey-Chretien "Faulkes Telescope South"
at Siding Spring also show cometary appearance; six stacked 60-s R-band
exposures taken in good seeing conditions on Oct. 19.6 UT show a sharp central
condensation, a compact coma about 5" in diameter, and a wide, fan-shaped tail
at least 45" long toward p.a. 250 deg.  Five stacked 60-s R-band follow-up
images taken by Sostero, Howes, and Guido with the 2.0-m "Faulkes Telescope
North" at Haleakala on Oct. 20.4 again show a sharp central condensation, a
compact coma about 6" in diameter, and a tail at least 30" long toward p.a.
247 deg.
     After two nights of observations of Grauer's comet had been received at
the Minor Planet Center, T. Spahr realized that this object was identical
with an object discovered a year ago by the LINEAR project (discovery
observation tabulated below; cf. MPS 351583) that appeared to be a Jupiter
Trojan minor planet.

     2010 UT             R.A. (2000) Decl.       Mag.   Observer
     Oct.  1.30866   23 59 35.07   - 2 29 22.4   19.4   LINEAR
           1.34812   23 59 34.05   - 2 29 29.5   19.6     "

     2011 UT             R.A. (2000) Decl.       Mag.   Observer
     Oct. 19.33795    1 58 19.45   +11 16 39.2   19.1   Grauer
          19.39053    1 58 17.94   +11 16 32.1   19.2     "
          19.44946    1 58 16.20   +11 16 24.3   19.2     "

     The new astrometry, the following linked orbital elements by G. V.
Williams, and an ephemeris appear on MPEC 2011-U41.

                    Epoch = 2011 Aug. 27.0 TT
     T = 2008 Aug. 27.9051 TT         Peri. = 250.1754
     e = 0.094391                     Node  =  43.8976  2000.0
     q = 5.065565 AU                  Incl. =   2.6503
       a =  5.593548 AU    n = 0.0745029    P =  13.23 years



NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 October 21                  (CBET 2867)              Daniel W. E. Green