[IAUC] CBET 3638: 20130826 : COMET C/2013 P4 (PANSTARRS)

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                                                  Electronic Telegram No. 3638
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 en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2013 P4 (PANSTARRS)
     Richard Wainscoat, Peter Veres, Marco Micheli, Larry Denneau, and Bryce
Bolin report the discovery of a comet in CCD exposures from the Pan-STARRS1
telescope on Haleakala (discovery observations tabulated below); the object
showed a distinctly non-stellar appearance, was a coma extending for about 5",
appearing as an asymmetric coma or with a possible tail extending towards
position angle approximately 190 degrees.  Follow-up images obtained on Aug.
16.46 UT with the 2.24-m University of Hawaii reflector by Micheli (and
measured with D. J. Tholen) show the object to be clearly diffuse.  After
posting on the Minor Planet Center's NEOCP webpage, other CCD astrometrists
have commented on the object's cometary appearance.  H. Sato (Tokyo, Japan)
obtained images remotely with an iTelescope.net 0.43-m f/6.8 astrograph (+
luminance filter) at Siding Spring on Aug. 17.8 that show a 10" coma of mag
19.4 as measured within a circular aperture of radius 5".5; no tail was visible
in sixteen stacked 60-s exposures.  Follow-up images with a 0.51-m f/6.8
astrograph (+ luminance filter) at Siding Spring on Aug. 26.5 show an outer
coma 25" in diameter of magnitude 17.9 as measured within a circular aperture
of radius 13".0, and again with no tail.  E. Guido (Castellammare di Stabia,
Italy) reports that nine stacked 60-s R-band images taken remotely by K.
Rochowicz, N. Howes, and himself on Aug. 26.5 with the 2.0-m f/10 "Faulkes
Telescope South" at Siding Spring show a sharp central condensation surrounded
by a coma of diameter about 15".

     2013 UT             R.A. (2000) Decl.       Mag.
     Aug. 15.49380   22 51 52.27   - 1 49 54.6   20.8
          15.50936   22 51 51.97   - 1 49 56.0   20.8
          15.52491   22 51 51.69   - 1 49 57.3   20.8
          15.54046   22 51 51.39   - 1 49 58.7   20.8

The available astrometry, the following preliminary parabolic orbital elements
by G. V. Williams, and an ephemeris appear on MPEC 2013-Q34.

     T = 2015 June 23.5919 TT         Peri. = 157.5038
                                      Node  = 256.8410  2000.0
     q = 4.404715 AU                  Incl. =   4.3316


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

                         (C) Copyright 2013 CBAT
2013 August 26                   (CBET 3638)              Daniel W. E. Green