Electronic Telegram No. 4354
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 C/2017 B3 (LINEAR)
     An apparently asteroidal object found on CCD images obtained 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 (discovery observations
tabulated below) has been found to show cometary appearance by CCD
astrometrists elsewhere after the object was posted on the Minor Planet
Center's NEOCP and PCCP webpages.

     2017 UT             R.A. (2000) Decl.       Mag.
     Jan. 26.43489   12 55 27.44   -24 29 59.2   19.2
          26.43972   12 55 27.37   -24 30 00.6   19.0
          26.44461   12 55 27.34   -24 30 01.8   19.6
          26.45417   12 55 27.24   -24 30 05.0   19.2
          26.45893   12 55 27.22   -24 30 06.6   19.4

S. Foglia writes (on behalf also of L. Buzzi, P. Concari, C. Cremaschini, G.
Galli, and M. Tombelli) that ten stacked images taken on Jan. 28.6 UT with an
iTelescope 0.15-m f/7 refractor at Siding Spring reveal a round, compact coma
6" in diameter (FWHM being 30 percent larger than images of nearby stars)
with red magnitude 18.2-18.4; twelve stacked follow-up images taken on Jan.
30.7 show a coma of size 6" x 10", elongated toward p.a. 300 (red mag 18.8-
18.9).  K. Sarneczky, Konkoly Observatory, report that twelve stacked 120-s
unfiltered CCD images taken with the 0.60-m Schmidt telescope at Piszkesteto,
Hungary, on Jan. 28.1 show a condensed, slightly fuzzy coma that is "softer"
than the nearby stars; the R-band magnitude was 18.7 as measured within a
circular aperture of radius 5".0.  G-band images taken by W. H. Ryan and E.
V. Ryan on Jan. 30.44-30.46 with the Magdalena Ridge Observatory 2.4-m f/8.9
reflector show a distinct coma and a small tail toward p.a. about 325 deg.
H. Sato, Tokyo, Japan, writes that ten stacked images taken with a 0.61-m
f/6.5 astrograph (+ luminance filter) at the Sierra Remote Observatory,
Auberry, CA, USA, on Jan. 31.5 show a strongly condensed coma 8" in diameter
with no tail, and  w-band magnitude 18.4 as measured within a circular
aperture of radius 5".0.
     The available astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2017-C45.

     T = 2019 Jan. 29.7681 TT         Peri. = 285.7864
                                      Node  =   2.1121  2000.0
     q = 3.839955 AU                  Incl. =  54.0582


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2017 CBAT
2017 February 4                  (CBET 4354)              Daniel W. E. Green