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IAUC 8835: C/2006 WD_4; 187P

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IAUC number

                                                  Circular No. 8835
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://www.cfa.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)

     E. Guido and G. Sostero, Castellammare di Stabia, Italy,
report that their remote CCD observations with a 0.15-m f/6
reflector at the 'Rent-a-Scope' Observatory at Biggera Waters,
Queensland, show the Mt. Lemmon discovery 2006 WD_4 (cf. MPEC
2006-W61, MPC 189005; discovery observation tabulated below) to be
a comet.  The co-addition of eleven unfiltered 60-s exposures on
Apr. 30.80 UT revealed the presence of a spiral-like symmetric coma,
spanning almost 20", from p.a. 240 deg to p.a. 30 deg (in a
counterclockwise direction); the total magnitude was close to 14.2,
and that of the condensation was 15.3-15.4.  The coaddition of nine
similar exposures (but in less satisfactory conditions) on May 2.80
showed the presence of an elliptical coma measuring nearly 12" x
18", the major axis tilted along a line close to p.a. 235 deg; the
total mag was about 14.1 and that of the condensation 15.4.

     2006 UT             R.A. (2000) Decl.       Mag.
     Nov. 20.32650    3 32 32.53   +28 02 22.0   20.3

     The following orbital elements, together with the Apr. 30-May
2 astrometry, full residuals, and an ephemeris, are given on MPEC

                    Epoch = 2007 Apr. 10.0 TT
     T = 2007 Apr. 28.3951 TT         Peri. = 292.6928
     e = 0.998994                     Node  = 226.7908  2000.0
     q = 0.591207 AU                  Incl. = 152.7038

     With reference to observations by F. Bernardi with the 2.24-m
University of Hawaii reflector on 2006 Dec. 25.4 UT, D. J. Tholen
wrote that, although the object appeared stellar to the eye, the
CCD trail of 2006 WD_4 was wider than the trails of two dozen stars
nearby.  In the second of the 600-s exposures, the mean stellar
trail width was 2.08 +/- 0.05 pixels (0".91); that of 2006 WD_4
(FWHM) was 2.3 pixels (1".01), about 0.1 pixel wider than the
widest of the stellar sources.  The results were considered
"sufficiently suspicious to warrant further observations as the
object approaches the sun".

     Comet P/1999 J5 = 2007 E3 (cf. IAUC 8827) has been assigned
the permanent number 187P (cf. MPC 59555).

                      (C) Copyright 2007 CBAT
2007 May 10                    (8835)            Daniel W. E. Green

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