Electronic Telegram No. 4205
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)
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Prepared using the Tamkin Foundation Computer Network


COMET P/2015 W2 (CATALINA)
     An apparently asteroidal object discovered in CCD images obtained by
J. A. Johnson and G. J. Leonard in the course of the Catalina Sky Survey
(discovery observations tabulated below) has been found by other CCD
astrometrists to show cometary appearance after the object was posted on
the Minor Planet Center's PCCP webpage.

     2015 UT             R.A. (2000) Decl.       Mag.   Observer
     Nov. 21.21863    4 33 59.95   +35 23 36.4   18.8   Johnson
          21.23078    4 33 59.51   +35 23 36.4   18.8     "
          21.23686    4 33 59.24   +35 23 34.0   18.9     "

V-band observations obtained by W. H. Ryan and E. V. Ryan with the Magdalena
Ridge Observatory 2.4-m f/8.9 reflector in New Mexico in very bad seeing on
Nov. 21.3 UT show a faint hint of a tail at p.a. about 235 deg; longer
exposures taken on Nov. 21.4 show a definite tail in p.a. about 235 deg, and
additional frames taken on Nov. 22.24-22.34 and 23.34-23.36 show the faint
tail in the same direction (noted as a broad tail on Nov. 22, and the bright
moonlight noted on Nov. 23).  H. Sato, Tokyo, Japan, obtained ten stacked 60-s
exposures with an iTelescope 0.61-m f/6.5 astrograph (+ luminance filter) at
the Sierra Remote Observatory near Auberry, CA, USA, which show the comet to
be strongly condensed with a coma 10" in diameter and no tail, with a w-band
of 18.6 as measured within a circular aperture of radius 5".0.  R. Haver,
Frasso Sabino, Italy, writes that fifteen stacked 90-s exposures taken with
a 36.9-cm f/6.8 Cassegrain telescope on Nov. 29.81 show a 4".2 coma (in 3".0
seeing).
     The available astrometry, the following preliminary elliptical orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2015-W73.

     T = 2015 Oct.  2.9651 TT         Peri. = 118.2718
     e = 0.631748                     Node  = 294.1972  2000.0
     q = 2.679332 AU                  Incl. =  11.6155
       a =  7.275807 AU    n = 0.0502206    P =  19.63 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 November 30                 (CBET 4205)              Daniel W. E. Green