Electronic Telegram No. 3916
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 M2 (CHRISTENSEN)
     E. J. Christensen reports his discovery of a comet on CCD images taken
with the Mount Lemmon 1.5-m reflector (discovery observations tabulated
below), the object showing a diffuse 5" coma elongated toward the southwest
in stacked images, adding that it appears in one of the dark lanes of the
Milky Way.

     2014 UT             R.A. (2000) Decl.       Mag.   Observer
     June 25.31442   18 39 42.30   - 0 06 28.3   19.4   Christensen
          25.32051   18 39 42.19   - 0 06 28.1            "
          25.32658   18 39 42.07   - 0 06 26.6            "
          25.33266   18 39 41.94   - 0 06 25.8            "
          25.36316   18 39 41.35   - 0 06 21.1   19.7     "
          25.38124   18 39 40.93   - 0 06 18.2            "

After posting on the Minor Planet Center's PCCP webpage, other CCD
astrometrists have commented on the object's cometary appearance.  H. Sato
(Tokyo, Japan) obtained ten stacked 60-s exposures using an iTelescope 0.51-m
f/6.8 astrograph (+ luminance filter) at Siding Spring on June 25.5 UT, which
show a strongly condensed coma 8" in diameter and no tail, with w-band
magnitude 20.2 as measured within a circular aperture of radius 6".5; ten
stacked 60-s follow-up images on June 26.6 show a similar appearance.
M. Micheli and E. Schwab report that they analyzed images obtained on June
26.0 by D. Abreu with the 1.0-m telescope of the European Space Agency's
Optical Ground Station at Tenerife, Canary Islands; nine stacked 90-s images
show a non-stellar point-spread function with a marginal asymmetric extension
of the coma toward the southwest; the coma had FWHM around 3".8 in 3".0
seeing, and they measured red mag 19.5-20.1.

The available astrometry, the following very preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2014-N02.

     T = 2013 Jan. 15.5329 TT         Peri. = 358.0074
                                      Node  = 261.0140  2000.0
     q = 8.256915 AU                  Incl. =  48.9794


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2014 CBAT
2014 July 1                      (CBET 3916)              Daniel W. E. Green