Electronic Telegram No. 3039
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 C/2012 BJ_98
     A comet found by Alex R. Gibbs and Eric J. Christensen on images taken
last night with the Mount Lemmon Survey's 1.5-m reflector has been identified
at the Minor Planet Center with an apparently asteroidal object found also via
the Mount Lemmon Survey on images taken by Rik Hill on Jan. 26 (and designated
2012 BJ_98 at the time based also on Pan-STARRS astrometry from Jan. 26 and
on Catalina astrometry from Jan. 31; cf. MPS 410364).  Gibbs and Christensen
reported the object to have a clearly diffuse 8" coma that was elongated
toward p.a. 120 deg (but with no clear tail visible) on four co-added 30-s
exposures taken in fair (about 2") seeing on Mar. 1.2 UT.  After he learned
of Mount Lemmon astrometry from Feb. 10 that had been previously reported to
the MPC, Christensen looked closely at those images and reports that all four
images were taken in relatively poor seeing and with a bright sky background,
adding that he cannot distinguish any coma or tail; he further adds that
additional Mt. Lemmon images taken by R. A. Kowalski on Feb. 24.2 show a
slightly diffuse appearance when compared to stars of similar magnitude.

     2012 UT             R.A. (2000) Decl.       Mag.   Observer
     Jan. 26.25215    8 12 27.36   +19 50 29.5   19.2   Hill
          26.25737    8 12 27.14   +19 50 30.3   19.4     "
          26.26262    8 12 26.92   +19 50 31.5   19.4     "
          26.26789    8 12 26.71   +19 50 32.3   19.3     "
     Mar.  1.21215    7 51 51.71   +21 16 54.3   19.1   Gibbs
           1.22024    7 51 51.53   +21 16 54.8            "
           1.22844    7 51 51.36   +21 16 55.6            "
           1.23655    7 51 51.23   +21 16 55.9            "

The available astrometry (including prediscovery Spacewatch observations
from 2011 Dec. 29, 2012 Jan. 6, and Jan. 14), the following elliptical
orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2010-E14.

                    Epoch = 2012 Sept.30.0 TT
     T = 2012 Sept.20.6066 TT         Peri. =  72.9939
     e = 0.873732                     Node  = 124.0279  2000.0
     q = 2.156879 AU                  Incl. =   2.6397
       a = 17.081789 AU    n = 0.0139606    P =  70.6 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 March 2                     (CBET 3039)              Daniel W. E. Green