Electronic Telegram No. 4358
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/2017 C1 (NEOWISE)
     James Bauer, Jet Propulsion Laboratory, reports the discovery of
another comet found on infrared images taken with the Near-Earth Object
Wide-field Infrared Survey Explorer (or NEOWISE; formerly the WISE earth-
orbiting satellite; cf. CBET 4225).  The discovery observations are tabulated
below, in which the listed optical-wavelength magnitude was roughly estimated
based on past WISE and NEOWISE cometary observations.  The images appeared to
show a weak extended coma, but Bauer wasn't absolutely sure, and the object
was posted on the Minor Planet Center's NEOCP webpage.

     2017 UT             R.A. (2000) Decl.        Mag.
     Feb.  6.09420   17 22 14.63   +60 41 48.9     19
           6.09433   17 22 14.82   +60 41 50.0
           6.22523   17 21 51.51   +60 44 56.6
           6.35627   17 21 28.12   +60 48 02.8
           6.48717   17 21 04.25   +60 51 10.5
           6.61820   17 20 40.41   +60 54 17.4
           6.74911   17 20 16.05   +60 57 30.1
           6.88014   17 19 51.79   +61 00 39.0

Follow-up CCD images were obtained by W. H. Ryan and E. V. Ryan at Magdalena
Ridge Observatory with the 2.4-m f/8.9 reflector (+ G-band filter) on Feb.
10.45-10.47 UT, showing a distinct coma and wide tail elongated toward p.a.
about 325 deg (magnitude 19.6-20.0); additional images taken on Feb. 11.4
clearly show a coma even in poor atmospheric conditions.
     The available astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2017-C82.

     T = 2017 Jan. 21.9258 TT         Peri. = 112.3211
                                      Node  = 356.7189  2000.0
     q = 1.528994 AU                  Incl. =  66.8272


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2017 CBAT
2017 February 12                 (CBET 4358)              Daniel W. E. Green