Electronic Telegram No. 4311
Central Bureau for Astronomical Telegrams
Mailing address:  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/2016 Q2 (PANSTARRS)
     E. Lilly, R. Weryk, and R. Wainscoat report the discovery of another
comet in three w-band exposures obtained with the 1.8-m Pan-STARRS1 telescope
at Haleakala on Aug. 26 UT (discovery observations tabulated below); in
each image, the object shows a broad low-surface-brightness tail extending
towards the north for approximately 6".  The full-width-at-half-maximum of
the nuclear condensation in a co-added image is 1".7, compared to 1".1 for
adjacent stars.

     2016 UT             R.A. (2000) Decl.       Mag.
     Aug. 26.34127   21 30 20.26   -12 55 46.4   21.6
          26.35378   21 30 19.97   -12 55 47.1   21.4
          26.36630   21 30 19.69   -12 55 47.1   21.4

After the comet was posted on the Minor Planet Center's PCCP webpage, other
CCD astrometrists have also commented on the object's cometary appearance.
H. Sato, Tokyo, Japan, writes that sixteen stacked 60-s images taken with
an iTelescope 0.51-m f/6.8 astrograph (+ luminance filter) located at Siding
Spring on Aug. 27.6 UT show a strongly condensed coma 12" in diameter and
no tail; the w-band magnitudes was 19.1 as measured within a circular
aperture of radius 6".5.  Thirty co-added 30-s images taken by R. Holmes
(Ashmore, IL, USA) with a 1.3-m f/4 astrograph at Westfield, IL, on Aug.
28.2 show a round 6".1 coma and a very broad 12".0 tail in p.a. 338 deg.
     The available astrometry, the following preliminary orbital elements
by G. V. Williams (from 17 observations spanning Aug. 26-30), and an
ephemeris appear on MPEC 2016-Q53.

     T = 2020 Jan.  3.4689 TT         Peri. = 111.0386
                                      Node  = 321.1825  2000.0
     q = 3.433919 AU                  Incl. =  62.9565


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2016 CBAT
2016 August 31                   (CBET 4311)              Daniel W. E. Green