Electronic Telegram No. 3736
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/2013 X1 (PANSTARRS)
     Bryce Bolin, Larry Denneau, Peter Veres, and Richard Wainscoat report
their discovery of a comet with a diffuse, non-stellar appearance in four
45s w-band exposures from the Pan-STARRS1 telescope on Haleakala (discovery
observations tabulated below).  A stacked image showed no sign of a tail.

     2013 UT             R.A. (2000) Decl.       Mag.
     Dec.  4.43435    7 13 41.74   +31 30 34.0   20.2
           4.44831    7 13 41.27   +31 30 35.6   20.3
           4.46232    7 13 40.79   +31 30 37.5   20.2
           4.47630    7 13 40.31   +31 30 39.1   20.2

Marco Micheli writes that follow-up images were obtained by R. J. Wainscoat on
Dec. 5.5 UT with the 3.6-m Canada-France-Hawaii Telescope (queue observer David
Woodworth); an analysis of these images by Wainscoat and Micheli confirms the
cometary activity of this object, with three 180-s r-band exposures showing a
non-stellar point-spread function (FWHM about 1".3 in 0".9 seeing conditions)
and a short tail about 2" long in p.a. 30 deg.  After the object was posted on
the Minor Planet Center's PCCP webpage, H. Sato (Tokyo, Japan; remotely with
an iTelescope 0.51-m f/6.8 astrograph at Siding Spring; Dec. 5.7) found a
moderately condensed coma 6" in diameter.

     The available astrometry (including pre-discovery observations from Nov.
29 at Mount Lemmon giving magnitude 19.9-20.0), the following preliminary
parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC
2013-X28.

     T = 2016 Apr. 18.8438 TT         Peri. = 164.7787
                                      Node  = 130.9630  2000.0
     q = 1.298993 AU                  Incl. = 163.2416


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 December 6                  (CBET 3736)              Daniel W. E. Green