Electronic Telegram No. 4266
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/2016 E2 (KOWALSKI)
     R. A. Kowalski reports the discovery of a diffuse comet with a coma
diameter approximately 8"-10" and a short stubby tail in p.a. 275 degrees on
CCD images obtained with the 0.68-m Schmidt telescope in the course of the
Catalina Sky Survey on Mar. 15.44-15.46 UT; follow-up 60-s exposures on Mar.
15.49-15.51 show a coma approximately 12"-15" in diameter but no obvious tail
(observations tabulated below).  Four co-added 60-s images taken by Kowalski
on Mar. 16.3 show a coma approximately 25" in diameter (magnitude 17.3-17.7)
with the impression of a broad, faint tail a few arcsec long in p.a. 255 deg.

     2016 UT             R.A. (2000) Decl.       Mag.   Observer
     Mar. 15.44113   14 19 32.24   + 0 42 59.6   17.7   Kowalski
          15.44719   14 19 25.99   + 0 44 47.8   17.9     "
          15.45324   14 19 19.65   + 0 46 36.6   18.7     "
          15.45931   14 19 13.44   + 0 48 24.6   17.7     "
          15.49345   14 18 37.61   + 0 58 36.6   18.0     "
          15.50032   14 18 30.47   + 1 00 40.3   17.4     "
          15.51407   14 18 16.14   + 1 04 46.3   17.6     "

Follow-up CCD mosaic 50-s images obtained by A. F. Tubbiolo with the
Spacewatch 0.9-m f/3 reflector at Kitt Peak on Mar. 15.52 UT show a comet with
a tail 20" long in p.a. approximately 200 deg.  After posting on the Minor
Planet Center's PCCP webpage, other CCD astrometrists also commented on the
object's cometary appearance.  Sixty-five stacked 15-s unfiltered exposures
taken by E. Guido and N. Howes remotely on Mar. 16.4 with an iTelescope
0.25-m f/3.4 reflector in New Mexico reveal a diffuse, irregular coma nearly
10" in diameter.  V-band images obtained by W. H. Ryan and E. V. Ryan with
the Magdalena Ridge Observatory 2.4-m f/8.9 reflector on Mar. 16.4 show a
distinct coma extended toward p.a. about 225 deg.
     The available astrometry (spanning Mar. 15-16), the following preliminary
parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC

     T = 2016 Feb.  6.7030 TT         Peri. = 322.0073
                                      Node  = 186.6663  2000.0
     q = 1.075666 AU                  Incl. = 136.0051


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2016 CBAT
2016 March 16                    (CBET 4266)              Daniel W. E. Green