Electronic Telegram No. 3083
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/2012 G1 (PANSTARRS)
     Larry Denneau, Richard Wainscoat, Henry Hsieh, Peter Veres, and Bryce
Bolin report the discovery of a comet in four exposures taken with the 1.8-m
Pan-STARRS 1 telescope at Haleakala (discovery observations tabulated below),
with the object having a soft appearance, with a point-spread function with
FWHM of approximately 1".1, compared to nearby stars that have FWHM of
approximately 0".9; a broad, faint tail is seen extending for approximtately
7" to the northwest.  Henry Hsieh obtained three 120-s follow-up exposures
with the 4.1-m Southern Astrophysical Research (SOAR) Telescope (+ Bessell R
filter) on Apr. 14.10 UT, confirming that the object appears distinctly
cometary; a composite image shows a broad, faint tail to be clearly visible
extending approximately 5" to the northwest (p.a. about 315 deg).  After
posting on the Minor Planet Center's NEOCP webpage, other CCD astrometrists
have also noted the object's cometary appearance.  H. Sato (Tokyo, Japan;
remotely using a 0.51-m f/6.8 astrograph + f/4.5 focal reducer at the RAS
Observatory near Mayhill, NM, U.S.A.; Apr. 14.3) finds the comet to be
poorly condensed with a coma diameter of 13", elongated toward p.a. 240
degrees; the total V-band magnitude was measured within a circular aperture
of radius 6".6 to be 19.9.  Two 60-s R-band images taken remotely by K.
Rochowicz, G. Sostero, E. Guido, and N. Howes with the 2.0-m f/10 "Faulkes
Telescope North" at Haleakala on Apr. 16.4 show a sharp central condensation
and a tail nearly 5" long in p.a. 100 deg; L. Buzzi writes that additional
stacked images taken with the same telescope by P. Miller, P. Roche, A.
Tripp, R. Miles, R. Holmes, S. Foglia, and himself on Apr. 16.4 show the
object to be diffuse.

     2012 UT             R.A. (2000) Decl.       Mag.
     Apr. 13.35047   12 04 33.74   -20 51 01.4   21.1
          13.36369   12 04 33.29   -20 50 57.1   20.9
          13.37693   12 04 32.85   -20 50 52.7   21.0
          13.39016   12 04 32.39   -20 50 48.5   21.0

The available astrometry, the following preliminary elliptical orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2012-H17.

     T = 2012 June  1.4325 TT         Peri. = 286.1149
     e = 0.380722                     Node  = 282.5440  2000.0
     q = 2.584166 AU                  Incl. =  11.6925
       a =  4.172871 AU    n = 0.1156250    P =   8.52 years


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

                         (C) Copyright 2012 CBAT
2012 April 17                    (CBET 3083)              Daniel W. E. Green