Electronic Telegram No. 4314
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 Q4 (KOWALSKI)
     R. A. Kowalski reports his discovery of a comet with a condensed coma
approximately 8" in diameter on CCD images taken with the Mount Lemmon 1.5-m
reflector (discovery observations tabulated below); there is a fan-shaped,
diffuse tail extending about 30" toward p.a. 260 degrees.

     2016 UT             R.A. (2000) Decl.       Mag.   Observer
     Aug. 30.24988   22 28 04.63   - 1 19 25.1   18.7   Kowalski
          30.25888   22 28 04.48   - 1 19 25.8   18.2     "
          30.26779   22 28 04.22   - 1 19 25.8   18.7     "
          30.27678   22 28 04.16   - 1 19 27.4   18.8     "
          30.34010   22 28 02.90   - 1 19 33.2   19.2     "
          30.34844   22 28 02.75   - 1 19 34.0   18.8     "
          30.35688   22 28 02.61   - 1 19 34.2   19.1     "
          30.36521   22 28 02.46   - 1 19 35.2   19.0     "

After the object was posted on the Minor Planet Center's PCCP webpage, other
CCD astrometrists have also commented on the cometary appearance.  P.
Birtwhistle, Great Shefford, Berkshire, England, writes that images taken
with a 0.40-m f/6.0 Schmidt-Cassegrain reflector on Aug. 30.9 UT show the
object to be diffuse, with a soft appearance and with a FWHM about 20 percent
larger than nearby stars of similar magnitude; the coma was measured to be
7"-9" in diameter, but there was a 12th-magnitude star on 30" away.  H. Sato,
Tokyo, Japan, stacked sixteen 60-s exposures obtained with a 0.43-m f/6.8
astrograph (+ luminance filter) at Nerpio, Spain, which reveal the object
to be moderately condensed with a coma 6" in diameter and no tail on Aug.
30.98; the w-band magnitude was 19.4 as measured within a circular aperture
of radius 3".8.  K. Sarneczky, Konkoly Observatory; and P. Szekely,
University of Szeged, report that twelve stacked 120-s unfiltered images
taken with the 0.60-m Schmidt telescope at Piszkesteto, Hungary, on Aug.
31.9 show a condensed coma 10" in diameter and two tails; the primary is
15" long at p.a. 250 deg, while the secondary is slightly curved, 10"
long toward about p.a. 340 deg.  Sarneczky adds that the R-band magnitude
was 19.7 as measured within a circular aperture of radius 5".0.  G. Baj,
Varese, Italy, reports a compact coma of red mag 19.1 on images taken on
Sept. 1.0 with a 0.30-m f/8 Ritchey-Chretien telescope.
     R. Weryk found pre-discovery images on exposures obtained with the
1.8-m Pan-STARRS1 telescope at Haleakala on July 11.54-11.55 UT (w-band
magnitude 22.2, with a short tail extending about 4" toward the west)
and on Aug. 3.5 (mag 21.8-22.2, with a tail as on July 11).
     The available astrometry, the following elliptical orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2016-R18.

                    Epoch = 2018 Feb. 11.0 TT
     T = 2018 Jan. 29.08680 TT        Peri. =  99.55312
     e = 0.5791117                    Node  = 271.31588 2000.0
     q = 7.0822057 AU                 Incl. =   7.25748
       a = 16.8268076 AU   n = 0.01427912   P =  69.02 years


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

                         (C) Copyright 2016 CBAT
2016 September 2                 (CBET 4314)              Daniel W. E. Green