[IAUC] IAUC 9225: C/2011 P2 [25139-2012/04-R1]

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                                                  Circular No. 9225
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 en EPS.HARVARD.EDU           ISSN 0081-0304
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Prepared using the Tamkin Foundation Computer Network


COMET C/2011 P2 (PANSTARRS)
     As first announced on CBET 2782, Richard Wainscoat, Institute
for Astronomy, University of Hawaii, reports (with Larry Denneau
and Henry Hsieh) the discovery of a comet on CCD images taken by N.
Primak, A. Schultz, S. Watters, J. Thiel, and T. Goggia with the
"Pan-STARRS 1" 1.8-m Ritchey-Chretien telescope at Haleakala
(discovery observations tabulated below); Wainscoat noted that the
point-spread function for the object is distinctly soft compared to
nearby stars on the discovery images.  Follow-up images by
Wainscoat and Marco Micheli with the Canada-France-Hawaii telescope
(+ r filter) again show the object to have cometary appearance.
Hsieh writes that images taken with the 2.24-m University of Hawaii
reflector on Aug. 4.5 UT shows a coma but no tail, as do additional
images taken by P. Forshay with the 3.6-m CFHT on Aug. 4.5
(measured by Wainscoat and Micheli).  After posting on the Minor
Planet Center's NEOCP website, other CCD astrometrists have also
commented on the object's cometary appearance.  T. Lister notes
that a coma is visible in his images taken on Aug. 5.4 with the
"Faulkes Telescope North" (2.0-m Ritchey-Chretien reflector) at
Haleakala.  H. Sato (Tokyo, Japan; remotely using a 0.51-m
reflector at the RAS Observatory near Mayhill, NM, U.S.A.; Aug.
7.24-7.25) finds a coma 8" in diameter with a total V magnitude of
19.4 as measured in an aperture of radius 4".9.  D. J. Tholen also
finds a distinct non-stellar profile of the object in images taken
by M. Micheli and G. T. Elliott on Aug. 7.30-7.45 with the 2.24-m
University of Hawaii reflector.

     2011 UT            R.A. (2000.0) Decl.       Mag.   Observer
     Aug.  3.39419   20 13 21.148  - 9 08 07.82   21.1   Pan-STARRS
           3.41744   20 13 20.619  - 9 08 10.08   20.6     "
           3.42785   20 13 20.354  - 9 08 11.48   20.7     "

The early astrometry appears on MPC 75578-75579; the following
orbital elements by G. V. Williams are from 41 observations (June
22-Aug. 27):

                    Epoch = 2010 Sept. 1.0 TT
     T = 2010 Sept.12.7182 TT         Peri. =  76.3203
     e = 0.371522                     Node  = 204.0061  2000.0
     q = 6.146854 AU                  Incl. =   8.9897
       a =  9.780545 AU    n = 0.0322225    P =  30.59 years

                      (C) Copyright 2011 CBAT
2011 September 11              (9225)            Daniel W. E. Green