Electronic Telegram No. 3857
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 H1 (CHRISTENSEN)
     Eric J. Christensen, Lunar and Planetary Laboratory, University of
Arizona, reports his discovery of a comet that is clearly diffuse with a
circular coma approximately 10" in diameter and no sign of a tail on four 30-s
Mount Lemmon survey images taken with the 1.5-m reflector (Ray J. Sanders also
present at the telescope); the discovery images are tabulated below.  Four
co-added 60-s follow-up images taken in good seeing by Christensen on Apr.
25.35-25.37 UT again show the coma as approximately 10" in diameter, slightly
elongated toward the southwest.

     2014 UT             R.A. (2000) Decl.       Mag.   Observer
     Apr. 24.41676   14 37 09.13   - 2 10 46.9   17.9   Christensen
          24.42335   14 37 07.20   - 2 10 56.8   18.1     "
          24.42993   14 37 05.28   - 2 11 07.7   18.1     "
          24.43652   14 37 03.37   - 2 11 18.1   18.5     "

After posting on the Minor Planet Center's PCCP webpage, other CCD
astrometrists have also commented on the object's cometary appearance.  Gianni
Galli (Pogliano Milanese, Italy; 0.28-m f/6.8 Schmidt-Cassegrain telescope;
Apr. 25.0) finds that stacked images show the object as clearly diffuse with a
6" coma.  H. Sato (Tokyo, Japan; remotely with an iTelescope 0.43-m f/6.8
astrograph near Mayhill, NM, U.S.A.; Apr. 25.2) found the object to be
strongly condensed with a coma of 8" to 10" in diameter, with w-band
luminance-filter magnitude 18.1 as measured within a circular aperture of
radius 7".6.

     The available astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2014-H33.

     T = 2014 Apr. 16.7725 TT         Peri. = 169.8088
                                      Node  =  34.6849  2000.0
     q = 2.142362 AU                  Incl. = 100.0808


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2014 CBAT
2014 April 25                    (CBET 3857)              Daniel W. E. Green