Electronic Telegram No. 3921
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; 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/2014 N3 (NEOWISE)
     James Bauer, Jet Propulsion Laboratory, reports the discovery of a comet
on stacked 3.4-micron images (discovery observations tabulated below) obtained
with the Near-Earth Object Wide-field Infrared Survey Explorer (or NEOWISE;
formerly the WISE satellite), the object described as extended with a faint
tail roughly anti-sunward; the estimated R-band magnitude based on preliminary
analysis is around 20.

     2014 UT             R.A. (2000) Decl.
     July  4.52350    1 51 17.50   -35 06 15.6
           4.78658    1 51 22.92   -35 06 07.6
           4.91825    1 51 25.53   -35 06 03.6
           5.04979    1 51 28.24   -35 06 01.4
           5.18133    1 51 30.82   -35 05 56.6

After the object was posted on the Minor Planet Center's NEOCP and PCCP
webpages, other ground-based CCD astrometrists have also commented on the
object's cometary appearance.  T. Lister writes that R-band images taken with
the 2.0-m Las Cumbres Observatory Global Telescope at Siding Spring on July
8.6-8.8 UT show a coma about 14" in diameter of mag 17.7-17.9 with a faint
tail about 2' long that has possibly some curvature.  H. Sato (Tokyo, Japan)
notes that twelve stacked 60-s exposures taken on July 8.76 with an
iTelescope 0.5-m f/6.8 astrograph (+ luminance filter) at Siding Spring show
a strongly condensed coma 30" in diameter with a wide tail 2' long toward p.a.
195 deg; its w-band magnitude as measured within a circular aperture of
radius 16".4 was 15.8.  E. Guido, N. Howes, and M. Nicolini obtained ten
stacked unfiltered 60-s exposures remotely with an iTelescope 0.5-m f/6.8
astrograph at Siding Spring on July 9.64 that reveal a coma about 15" in
diameter, elongated toward p.a. 200 deg; they measured a red magnitude of
16.4-16.8.  T. Prystavski reports that two 135-s exposures taken by A.
Novichonok on July 9.69-9.70 with an iTelescope 0.32-m f/9.3 Ritchey-Chretien
telescope (+ luminance filter) at Siding Spring show a moderate coma
approximately 0'.29 in diameter (total red mag 15.4) with a possible tail
about 1' long in p.a. 203 deg; Prystavski adds that two 46-s exposure taken
in bright moonlight by Novichonok on July 11.71 with an iTelescope 0.5-m
f/6.8 astrograph (+ luminance filter) at Siding Spring show a moderate coma
about 0'.3 in diameter and a tail about 0'.6 long in p.a. 195 deg.  M.
Urbanik, Cadca, Slovak Republic, writes that five stacked 30-s images taken
with an iTelescope 0.5-m f/6.8 astrograph at Siding Spring on July 10.8 in
good seeing shows it has a coma 20" wide with a tail at least 1' long
spanning p.a. 200-210 deg.  Ten stacked 60-sec images taken by C. Jacques,
E. Pimentel, and J. Barros with an iTelescope 0.5-m f/6.8 astrograph at
Siding Spring on July 11.7 reveal a diffuse coma 15" in diameter with a tail
1'.4 long in p.a. 192 degrees; the magnitude was measured as 15.9-16.0.
     The available astrometry, the following parabolic orbital elements by
G. V. Williams, and an ephemeris appear on MPEC 2014-N72.

     T = 2015 Mar. 15.6751 TT         Peri. = 354.4916
                                      Node  =  19.7184  2000.0
     q = 3.845609 AU                  Incl. =  61.7345


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

                         (C) Copyright 2014 CBAT
2014 July 13                     (CBET 3921)              Daniel W. E. Green