[IAUC] CBET 2874: 20111026 : COMET P/2011 U1 (PANSTARRS)

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 2874
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET P/2011 U1 (PANSTARRS)
     Larry Denneau, Richard Wainscoat, and Henry Hsieh, Institute for
Astronomy, University of Hawaii, report the discovery of a comet on CCD images
taken with the "Pan-STARRS 1" 1.8-m Ritchey-Chretien telescope at Haleakala
(discovery observations tabulated below); stacked discovery frames show FWHM
for the comet of 1".5, compared with 1".1 for nearby stars.  Confirming images
taken with the Canada-France-Hawaii Telescope by M. Micheli (measured by Hsieh)
show a diffuse, low-level coma with a slight extension (about 3"-4" long) to
the west.  After posting on the Minor Planet Center's NEOCP webpage, Shinsuke
Abe (Institute of Astronomy, National Central University, Jhongli, Taoyuan,
Taiwan) writes that stacked images taken by J. K. Guo, N. Panwar, W. P. Chen,
and himself on Oct. 26.4 UT (with a 0.81-m f/7 Ritchey-Chretien telescope at
the Tenagra II Observatory near Nogales, AZ, U.S.A.) show a tail-like structure
around p.a. 270 deg, though it is difficult to see clearly due to bad seeing
(about 2".2).

     2011 UT             R.A. (2000) Decl.       Mag.
     Oct. 23.45242    5 06 41.93   + 2 46 50.5   21.0
          23.46729    5 06 41.87   + 2 46 46.2   21.2
          23.48218    5 06 41.80   + 2 46 42.3   21.4
          23.49712    5 06 41.72   + 2 46 38.1   21.3

The available astrometry, the following preliminary elliptical orbital elements
by G. V. Williams, and an ephemeris appear on MPEC 2011-U84.

     T = 2012 June 29.230 TT          Peri. =   0.710
     e = 0.47609                      Node  = 133.997   2000.0
     q = 2.22570 AU                   Incl. =  15.380
       a =  4.24827 AU     n = 0.112560     P =   8.76 years


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 October 26                  (CBET 2874)              Daniel W. E. Green