Electronic Telegram No. 2878
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@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2011 U3 (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), noting that the point-spread
function (PSF) of the object's image is somewhat soft compared to nearby stars
and shows excesses compared to expected stellar PSFs.  Three images were
obtained using the Canada-France-Hawaii Telescope on Oct. 25 UT by Marco
Micheli and Richard Wainscoat (queue observer David Woodworth); Hsieh,
Wainscoat, and Denneau note that the object appears slightly extended when
compared to adjacent stars, with a stacked image yielding a FWHM of 1".15
(vs. FWHM = 0".85 for adjacent stars), with the coma appearing to be
spherically symmetric.

     2011 UT             R.A. (2000) Decl.       Mag.
     Oct. 24.54384    3 37 16.15   +22 56 22.1   21.8
          24.55909    3 37 14.65   +22 56 08.6   21.8
          24.57427    3 37 13.16   +22 55 55.5   22.1
          24.58950    3 37 11.63   +22 55 42.2   21.9

The available astrometry, the following preliminary parabolic orbital elements
by G. V. Williams, and an ephemeris appear on MPEC 2011-U107.

     T = 2012 June  2.2966 TT         Peri. = 288.5721
                                      Node  = 228.3770  2000.0
     q = 1.048827 AU                  Incl. = 116.3834


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 October 31                  (CBET 2878)              Daniel W. E. Green