Electronic Telegram No. 2113
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


COMET C/2010 A1 (HILL)
     R. E. Hill, Lunar and Planetary Laboratory, reports a cometary
object (discovery observation below) with the 0.68-m Schmidt at the Catalina
Sky Survey; in 2-4-arcsec seeing and moonlight, there was a 4-5-arcsec
condensation and a coma 10-15-arcsec across, with no obvious tail.  Four
coadded images obtained by E. C. Beshore with the Mt. Lemmon 1.5-m reflector
on Jan. 6.5 UT showed a very faint tail in p.a. 270 deg and perhaps 15" in
length.  After the discovery had been added to the NEO Confirmation Page,
Y. Ikari (Moriyama, Japan, 0.26-m f/7.0 reflector, Jan. 6.6) reported a
0'.2 coma; P. Birtwhistle (Great Shefford, Berkshire, England, 0.40-m f/6.0
Schmidt-Cassegrain, Jan. 7.1) described a weak condensation offset to the
southeast of a 15" by 22" coma, with the brightest part of the coma 6" by 12"
extending in p.a. 50 and 230 deg; and H. Sato (RAS Observatory, Mayhill, NM,
U.S.A., 0.25-m f/3.4 reflector, Jan. 7.2) mentioned a 20" coma elongated
in p.a. 110 deg.  On Jan. 7.2, Hill detected a short, fan-shaped tail,
20-30-arcsec long, in p.a. 270 deg.

     2010 UT             R.A. (2000) Decl.       Mag.   Observer
     Jan.  6.46381   09 11 26.44   +33 08 34.6   17.6   Hill

     Further astrometry, the following parabolic orbital elements and an
ephemeris are given on MPEC 2010-A31.  It is possible that the comet is of
short period.

     T = 2010 June 24.055 TT          Peri. = 219.047
                                      Node  =   6.140   2000.0
     q = 1.02031 AU                   Incl. =  11.782


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 January 7                   (CBET 2113)              Brian G. Marsden