Electronic Telegram No. 3721
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 W1 (PANSTARRS)
     Bryce Bolin, Jan Kleyna, Richard Wainscoat, Peter Veres, and Larry
Denneau report the discovery of a diffuse comet with a faint tail
approximately 2" long in p.a. approximately 70 degrees on four 45s w-band
exposures from the Pan-STARRS1 telescope on Haleakala (discovery astrometry
tabulated below).

     2013 UT             R.A. (2000) Decl.       Mag.
     Nov. 24.31002    3 03 09.49   + 7 49 20.3   20.7
          24.32334    3 03 08.68   + 7 49 18.7   20.7
          24.33666    3 03 07.87   + 7 49 16.9   20.8

After posting on the Minor Planet Center's PCCP webpage, H. Sato (Tokyo,
Japan) has obtained a series of CCD exposures with an iTelescope 0.51-m f/6.8
astrograph at Siding Spring over several days that also show the object's
cometary appearance:  on Nov. 25.5 UT, he found a diffuse coma 12" in
diameter and no tail with mag 18.8 as measured within a circular aperture of
radius 8".8; on Nov. 26.5, he found a moderately condensed coma of diameter
12", while on Nov. 27.6, he found a strongly condensed coma of diameter 10"
in stacked exposures.
     The available astrometry (including pre-discovery Catalina Sky Survey
observations from Nov. 9), the following elliptical orbital elements by G. V.
Williams, and an ephemeris appear on MPEC 2013-W23.

                    Epoch = 2014 Mar.  4.0 TT
     T = 2014 Mar.  7.9781 TT         Peri. =   1.2341
     e = 0.592539                     Node  = 117.8858  2000.0
     q = 1.415146 AU                  Incl. =   4.6918
       a =  3.473080 AU    n = 0.1522762    P =   6.47 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 November 27                 (CBET 3721)              Daniel W. E. Green