Electronic Telegram No. 4370
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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Prepared using the Tamkin Foundation Computer Network


COMET C/2017 E2 (XUYI)
     An apparently asteroidal object found on images taken by H. B. Zhao, B.
Li, G. Zhaori, R. Q. Hong, and L. F. Hu (and measured by Zhao, Li, H. Lu, and
G. Zhaori) with the Purple Mountain Observatory's 1.04-m f/1.8 Schmidt
telescope at its XuYi Station (discovery observations tabulated below) has
been found to show cometary activity elsewhere.

     2017 UT             R.A. (2000) Decl.       Mag.   Observer
     Mar.  1.82132   13 32 26.43   + 7 10 06.8   19.7   Zhao
           1.84135   13 32 25.01   + 7 10 04.9   19.5     "
           1.86138   13 32 23.57   + 7 10 02.2   19.5     "

The object was also found as apparently asteroidal on CCD images obtained
on Mar. 3.3 UT with the 3.5-m f/1 Space Surveillance Telescope on Atom Peak
in the White Sands Missile Range, NM, USA, in the course of the LINEAR
survey, and again posted on the Minor Planet Center's NEOCP, from which
follow-up G-band images were taken by W. H. Ryan and E. V. Ryan on Mar. 5.3
with the Magdalena Ridge Observatory 2.4-m f/8.9 reflector, which show the
object to be a comet of magnitude 19.4-19.6 with a tail in p.a.
approximately 300 degrees.
     Additional astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2017-E57.

     T = 2016 July 17.6357 TT         Peri. =  72.9190
                                      Node  =  14.8946  2000.0
     q = 1.528869 AU                  Incl. =  58.7721


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2017 CBAT
2017 March 7                     (CBET 4370)              Daniel W. E. Green