Electronic Telegram No. 3604
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 O2 (PANSTARRS)
     Bryce Bolin, Henry Hsieh, Richard Wainscoat, and Marco Micheli report
the discovery of a comet with a diffuse, non-stellar appearance and a tail
about 4".5 long in p.a. 250 degrees in four 45-s w-band exposures from the
Pan-STARRS1 telescope on Haleakala (discovery observations tabulated below).
The cometary appearance has been noted also by CCD astrometrists elsewhere
after the object was posted on the Minor Planet Center's 'NEOCP' webpage.
R. Holmes (Ashmore, IL, USA; 0.76-m f/3.0 astrograph) notes that forty-five
co-added 30-s exposures taken on July 17.4 UT show a round 5".5 coma of mag
19.0-19.5 and a broad, diffuse 15".3 tail in p.a. 284.8 deg.  T. Vorobjov
writes that eighty additional stacked 20-s exposures taken by Holmes with a
0.81-m f/4 astrograph at Ashmore on July 25.4 reveal a round coma of diameter
6" and a tail 18" long in p.a. 282 deg.  H. Sato (Tokyo, Japan; remotely using
a 0.32-m f/8 astrograph at the iTelescope Observatory near Nerpio, Spain, on
July 21.14) finds a strongly condensed coma 8" in diameter and a hint of a
tail 15" long toward p.a. 280 degrees; the V-band magnitude as measured within
a circular aperture of radius 5".8 was 18.5.  Additional exposures taken
remotely by Sato with an iTelescope 0.51-m f/6.8 astrograph at Siding Spring
on July 24.8 show a moderately condensed coma 10" in diameter on twelve
stacked 60-s images; the V-band magnitude as measured within a circular
aperture of radius 6".5 was 19.2.

     2013 UT             R.A. (2000) Decl.       Mag.
     July 16.59707    1 59 23.73   +16 48 43.5   20.6
          16.60195    1 59 24.16   +16 48 44.8   20.4
          16.60683    1 59 24.58   +16 48 46.3   20.7
          16.61171    1 59 25.01   +16 48 47.8   20.5

The available astrometry, the following elliptical orbital elements by G. V.
Williams, and an ephemeris appear on MPEC 2013-O53.

     T = 2013 Dec. 15.3697 TT         Peri. = 213.3498
     e = 0.445182                     Node  = 207.7279  2000.0
     q = 2.150681 AU                  Incl. =  13.3042
       a =  3.876370 AU    n = 0.1291416    P =   7.63 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 July 27                     (CBET 3604)              Daniel W. E. Green