Electronic Telegram No. 4263
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)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2016 E1 (PANSTARRS)
     R. J. Wainscoat and R. Weryk report the discovery of a comet on images
taken on Mar. 3 UT with the 1.8-m Pan-STARRS1 telescope at Haleakala
(discovery observations tabulated below); though faint, it appears extended
with FWHM = 1".3 compared to adjacent stars with FWHM = 1".0.

     2016 UT             R.A. (2000) Decl.       Mag.
     Mar.  3.54407   15 07 48.51   - 0 22 47.3   21.1
           3.55511   15 07 48.31   - 0 22 43.6   20.9
           3.56584   15 07 48.15   - 0 22 39.6   20.9
           3.57625   15 07 47.96   - 0 22 36.1   20.8

Confirming images taken by Wainscoat and D. Woodworth with the 3.6-m Canada-
France-Hawaii Telescope at Mauna Kea on Mar. 10.6 UT shows the comet at red
mag 20.7 with a short tail a few arcseconds long towards position angle
approximately 150 degrees (measured by M. Micheli and Wainscoat).  After
posting on the Minor Planet Center's PCCP webpage, other CCD astrometrists
have noted the object's cometary appearance.  H. Sato, Tokyo, Japan, obtained
eight stacked 60-s exposures on Mar. 4.67 with a 0.70-m f/6.6 astrograph (+
luminance filter) at Siding Spring, revealing a strongly condensed, compact
coma 6" in diameter with no tail; the w-band magnitude was 20.0 as measured
within a circular aperture of radius 3".3.  V-band images acquired by W. H.
Ryan and E. V. Ryan with the Magdalena Ridge Observatory 2.4-m f/8.9
reflector on Mar. 11.45-11.47 show a point-spread function about 1.5 times
larger than nearby field stars, with a "slight tail" in p.a. about 135 deg.
     The available astrometry (spanning Mar. 3-11), the following preliminary
parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC
2016-E113.

     T = 2017 Aug. 25.8441 TT         Peri. =  53.1879
                                      Node  = 233.0379  2000.0
     q = 7.914668 AU                  Incl. = 131.9804


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2016 CBAT
2016 March 11                    (CBET 4263)              Daniel W. E. Green