[IAUC] IAUC 8839: C/2007 K3; C/2007 K4 [25139-2008/05-R1]

Vie Jun 22 16:58:44 ART 2007

                                                  Circular No. 8839
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS en CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT en CFA.HARVARD.EDU (science)
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Phone 617-495-7440/7244/7444 (for emergency use only)

COMET C/2007 K3 (SIDING SPRING)
     An apparently asteroidal object discovered by G. Garradd in
the course of the Siding Spring Survey (discovery observation
tabulated below) was found by R. H. McNaught on three co-added
0.5-m Uppsala Schmidt telescope images from May 25.35-25.49 UT to
show a 6" coma that is slightly but certainly diffuse.

     2007 UT             R.A. (2000) Decl.       Mag.
     May  23.43266   11 45 57.24   -17 47 59.4   19.0

The available astrometry (including prediscovery Siding Spring
observations by McNaught from Apr. 18), the following preliminary
parabolic orbital elements, and an ephemeris appear on MPEC
2007-K56.

     T = 2008 Apr. 21.735 TT          Peri. =  23.561
                                      Node  = 263.299   2000.0
     q = 2.05102 AU                   Incl. =  16.295

COMET C/2007 K4 (GIBBS)
     A. R. Gibbs reports his discovery of a comet on Catalina Sky
Survey images taken with the 0.68-m Schmidt telescope (discovery
observation tabulated below), the object noted as having a compact
9" coma and a 15" tail spanning p.a. 0-30 deg on four co-added 30-s
unfiltered CCD images taken in good seeing.  Following posting on
the Minor Planet Center's 'NEOCP' webpage, R. H. McNaught writes
that his images of this object with the 0.5-m Uppsala Schmidt
telescope on May 25.6 UT show a 10" coma and a possible tail to the
north.  Also, R. E. Hill reports that four co-added 30-s Mt.
Lemmon images from May 26.35-26.36 show a broad tail about 1' long
in p.a. 10 deg and a slight coma about 2"-3" in diameter.

     2007 UT             R.A. (2000) Decl.       Mag.
     May  25.32443   16 56 28.69   - 4 37 46.0   18.2

The available astrometry, the following preliminary parabolic
orbital elements, and an ephemeris appear on MPEC 2007-K57.

     T = 2007 Nov. 12.567 TT          Peri. = 211.884
                                      Node  =  69.590   2000.0
     q = 2.85465 AU                   Incl. =  93.350

                      (C) Copyright 2007 CBAT
2007 May 26                    (8839)            Daniel W. E. Green