IAUC 9187: C/2010 KW_7

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                                                  Circular No. 9187
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
New postal address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
CBATIAU@EPS.HARVARD.EDU           ISSN 0081-0304
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Prepared using the Tamkin Foundation Computer Network


COMET C/2010 KW_7 (WISE)
     R. S. McMillan, University of Arizona, reported that the
presumed asteroidal object 2010 KW_7 discovered by the WISE
spacecraft (discovery observation tabulated below; cf. MPEC
2010-K29; IAUC 9180) appeared slightly more diffuse than nearby
stars in images taken with the Steward Observatory 0.9-m reflector
(+ CCD mosaic) on Oct. 18.5 UT.  J. V. Scotti also reported that
nine 120-s co-added R-band images taken on Oct. 18.5 with the 2.3-m
Bok telescope at Kitt Peak reveal a coma diameter of 8" with a very
faint tail extending about 9" in p.a. 215 deg.  Scotti's further
co-added images taken on Oct. 28.5 with the Spacewatch 1.8-m
reflector show a coma diameter of 6".3 (total mag 20.1-20.5) and a
broad, faint, fan-shaped tail extending 0'.14 spanning p.a. 222-305
deg.  McMillan also reports (via A. Mainzer, Jet Propulsion
Laboratory) that Scotti has measured a coma diameter of 8".5 on
images taken by T. H. Bressi with the 1.8-m Spacewatch II telescope
on Nov. 11 -- and with a coma diameter of 7".4 with a broad, fan-
shaped tail structure extending about 8".8 towards p.a. 180.3
degrees and faintly to a length of about 8".0 in p.a. 275.5 deg
(where the brightest part of the fan was) on R-band images taken by
McMillan, Scotti, and M. L. Terenzoni at the 2.3-m Bok telescope (+
90Prime CCD camera) also on Nov. 11.
     J. M. Bauer and J. D. Goguen, Jet Propulsion Laboratory (JPL),
California Institute of Technology, report (also via Mainzer) that
four 300-s R-band images of 2010 KW_7 were taken on Nov. 7.54-7.55
UT with the Palomar 5-m reflector in about 1".5 seeing; the stacked
images reveal a coma and a faint tail extension approximately 7"-8"
in p.a. 287 deg (or roughly anti-solar).
     T. Grav and M. Huber, Johns Hopkins University; and J. Bauer,
JPL, report (also via Mainzer) that eight stacked 90-s SDSS-r-band
images of 2010 KW_7, obtained during Nov. 2.44-2.46 UT with the
Apache Point Observatory's 3.5-m telescope (+ SPICAM CCD camera)
show an apparent coma and a faint tail 4"-5" long in p.a. 286 deg.

     2010 UT             R.A. (2000) Decl.       Observer
     May  16.06415    9 22 33.13   -21 18 18.8   WISE

     The following orbital elements by G. V. Williams are from 57
observations spanning 2010 May 16-Nov. 17.

                    Epoch = 2010 Oct. 11.0 TT
     T = 2010 Oct. 11.3479 TT         Peri. = 332.3059
     e = 0.974263                     Node  = 104.7603  2000.0
     q = 2.570377 AU                  Incl. = 147.0620

                      (C) Copyright 2010 CBAT
2010 November 23               (9187)            Daniel W. E. Green

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