Electronic Telegram No. 3473
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 P/2013 G4 (PANSTARRS)
     Peter Veres, Larry Denneau, Henry Hsieh, and Richard Wainscoat, Institute
for Astronomy, report the discovery of an apparent comet in images taken with
the 1.8-m Pan-STARRS1 telescope on Haleakala (discovery positions tabulated
below), the object having a diffuse, non-stellar appearance with a very faint,
broad tail (possibly as long as 10" in co-added images) towards p.a.
approximately 300 degrees.  Marco Micheli and Wainscoat obtained a set of
30-s sidereally guided follow-up images with the Canada-France-Hawaii
Telescope on Mauna Kea around Apr. 13.35 UT, showing an extended shape.  After
the object was posted on the Minor Planet Center's NEOCP webpage, H. Sato
(Tokyo, Japan) reported that images taken remotely with a 0.43-m f/6.8
astrograph at the iTelescope Observatory near Mayhill, NM, USA, on Apr. 15.4
show a moderately condensed coma 10" in diameter with V-band magnitude 20.1 as
measured within a circular aperture of radius 5".7 on six stacked 120-s images.
(Sato also noted another possible cometary object with a strongly condensed
coma of diameter 12" and mag 18.4 in a circular aperture of radius 7".6 that
was found less than 11' west and 18' north of P/2013 G4 but with different
motion -- 5'.2/day in p.a. 311 deg, according to S. Nakano.)

     2013 UT             R.A. (2000) Decl.       Mag.
     Apr. 12.48912   14 04 46.51   -20 29 05.3   20.7
          12.50299   14 04 45.92   -20 29 04.6   21.1
          12.51683   14 04 45.36   -20 29 03.9   20.8
          12.53071   14 04 44.78   -20 29 03.4   21.0

The available astrometry, the following preliminary elliptical orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2013-H05.

     T = 2013 Mar.  4.5578 TT         Peri. = 220.6513
     e = 0.384301                     Node  = 340.4626  2000.0
     q = 2.698381 AU                  Incl. =   6.0566
       a =  4.382629 AU    n = 0.1074242    P =   9.2 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 April 16                    (CBET 3473)              Daniel W. E. Green