[IAUC] IAUC 9188: (596); P/2010 W1 [25139-2011/04-R1]

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                                                  Circular No. 9188
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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 20 Oxford St.; Cambridge, MA  02138; U.S.A.
CBATIAU en EPS.HARVARD.EDU           ISSN 0081-0304
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Prepared using the Tamkin Foundation Computer Network


(596) SCHEILA
     S. M. Larson, Lunar and Planetary Laboratory, reports that
images of the main-belt minor planet (596), taken on Dec. 11.44-
11.47 UT with the 0.68-m f/1.8 Schmidt telescope at Catalina, show
the object to be in apparent outburst with a comet-like appearance,
showing a total V magnitude of about 13.4 and an envelope that
extends 2' north and 5' west of the central condensation.  As
detailed on CBETs 2583 and 2590, many other observers have
confirmed this comet-like appearance, noting a spiral structure
emanating from the condensed image of the minor planet itself that
appears like some of the spiral outbursts of comet 29P.  Alex Gibbs
has looked at recent Catalina images of (596) taken on Oct. 18,
Nov. 2, Nov. 11, and Dec. 3 -- remarking that the object appears
essentially starlike on the first three dates (with the object in
November being at V about 14.5), but that on Dec. 3.4 it shows some
slight diffuseness with V = 13.2.


COMET P/2010 W1 (GIBBS)
     A. R. Gibbs, Lunar and Planetary Laboratory, reports his
discovery of a comet (discovery observation tabulated below) on
Catalina Sky Survey images obtained with the 0.68-m Schmidt
telescope; four co-added 20-s discovery exposures show a "fuzzy"
coma of diameter 8" (and magnitude 18.1-18.6) with no visible tail
(FWHM larger than nearby stars of similar magnitude).  Four
additional co-added 60-s exposures by Gibbs from Nov. 27.25 UT show
the coma size as 11' x 8'.5, elongated in the direction of motion
(p.a. 85 deg), again with no visible tail.

     2010 UT             R.A. (2000) Decl.       Mag.   Observer
     Nov. 27.19184    0 28 06.74   + 2 48 02.9   18.3   Gibbs

This object was identified by T. B. Spahr on the Minor Planet
Center's "Daily Orbit Update" for Nov. 28 (MPEC 2010-W45) with the
following objects that had received minor-planet designations:
1996 TT_65, 2010 MS_75, 2010 RR_59, 2010 RN_141, 2010 SQ_31, and
2010 TL_69.  Astrometry, the following elliptical orbital elements
by G. V. Williams, and an ephemeris appear on MPEC 2010-X102.

                    Epoch = 2011 Feb.  8.0 TT
     T = 2011 Feb.  8.7360 TT         Peri. = 209.9164
     e = 0.640494                     Node  = 207.7835  2000.0
     q = 2.146935 AU                  Incl. =   6.3704
       a =  5.971900 AU    n = 0.0675360    P =  14.59 years

                      (C) Copyright 2010 CBAT
2010 December 14               (9188)            Daniel W. E. Green