Electronic Telegram No. 4382
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
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Prepared using the Tamkin Foundation Computer Network


COMET P/2017 G1 (PANSTARRS)
     R. Weryk and E. Lilly, Institute for Astronomy, University of Hawaii,
report the discovery of a diffuse comet on images obtained on Apr. 1.5 UT
with the 1.8-m Pan-STARRS1 telescope at Haleakala (discovery observations
tabulated below, together with prediscovery Pan-STARRS1 images from Mar. 25).
There is a possible tail extending about 5" towards the northeast.

     2017 UT             R.A. (2000) Decl.       Mag.
     Mar. 25.42796   12 46 15.60   - 9 48 50.2   21.4
          25.44006   12 46 15.14   - 9 48 47.5   22.0
          25.45218   12 46 14.68   - 9 48 44.6   22.7
          25.46431   12 46 14.27   - 9 48 41.3   21.5
     Apr.  1.45654   12 42 06.85   - 9 20 44.2   22.0
           1.46683   12 42 06.52   - 9 20 41.6   21.8
           1.47712   12 42 06.13   - 9 20 39.1   21.8

M. Micheli and R. J. Wainscoat report that three 60-s gri-filtered confirming
exposures of the comet were obtained by Wainscoat and D. Woodworth on Apr.
2.3 UT with the 3.6-m Canada-France-Hawaii Telescope at Mauna Kea, which
show a diffuse appearance and a tail-like extension to the east.
     The available astrometry, the following preliminary elliptical orbital
elements by G. V. Williams (from 22 observations spanning Mar. 25-Apr. 5),
and an ephemeris appear on MPEC 2017-G56.

                    Epoch = 2016 May  12.0 TT
     T = 2016 May  11.9592 TT         Peri. = 218.1586
     e = 0.659817                     Node  = 259.3968  2000.0
     q = 2.619693 AU                  Incl. =   3.5387
       a =  7.700839 AU    n = 0.0461208    P =  21.37 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2017 CBAT
2017 April 6                     (CBET 4382)              Daniel W. E. Green