Electronic Telegram No. 4161
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/2015 V2 (JOHNSON)
     J. A. Johnson reports the discovery of a comet on CCD images obtained
with the Catalina Sky Survey's 0.68-m Schmidt telescope on Nov. 3.5 UT
(discovery observations tabulated below), the object having a compact coma
approximately 10"-15" in diameter with a possible tail in p.a. about 225 deg.

     2015 UT             R.A. (2000) Decl.       Mag.   Observer
     Nov.  3.44273    8 18 13.15   +55 35 30.9   17.1   Johnson
           3.44889    8 18 13.22   +55 35 33.2            "
           3.45498    8 18 13.21   +55 35 35.1            "
           3.46114    8 18 13.43   +55 35 37.6            "
           3.46904    8 18 13.43   +55 35 38.8   17.1     "
           3.47649    8 18 13.58   +55 35 44.1   17.1     "
           3.48397    8 18 13.63   +55 35 47.0   17.2     "
           3.49144    8 18 13.79   +55 35 52.9   17.1     "

After the object was posted on the Minor Planet Center's NEOCP and PCCP
webpages, other CCD astrometrists have also noted the object's cometary
appearance.  Twenty stacked 60-s images obtained by C. Jacques, E. Pimentel,
and J. Barros with a 0.43-m f/4.3 reflector near Mayhill, NM, USA, on Nov.
3.5 UT show a condensed coma 5" in diameter that is elongated 9" towards
p.a. 260 deg.  D. Denisenko writes that R-band exposures taken by S. Nazarov
with a 0.70-m f/4 reflector at the Crimean Astrophysical Observatory,
Nauchnij, on Nov. 3.9 show a central condensation and a short tail in p.a.
250 deg.  V-band images taken by W. H. Ryan and E. V. Ryan with the
Magdalena Ridge Observatory 2.4-m f/8.9 reflector on Nov. 4.3 show a coma
and a small tail in p.a. about 250 deg.  H. Sato, Tokyo, Japan, relates that
eight stacked 60-s exposures taken on Nov. 4.33-4.34 with a 0.43-m f/6.8
astrograph near Mayhill show the comet to be strongly condensed with a coma
8" in diameter, no tail, and a w-band magnitude of 16.5 as measured within
a circular aperture of radius 5".7.  E. Guido, Castellammare di Stabia, Italy,
remarks that twelve stacked 120-s exposures, obtained remotely on Nov. 4.37
with an iTelescope 0.43-m f/6.8 astrograph near Mayhill, show a compact coma
nearly 10" in diameter, elongated toward p.a. 230 deg.  G. Baj reports that
images obtained on Nov. 5.1 with a 0.25-m f/8 Ritchey-Chretien reflector at
Saltrio, Italy, show a coma compact 5".1 wide with a tail 15" long in p.a.
236 deg.
     The available astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2015-V44.

     T = 2017 Feb. 14.7075 TT         Peri. = 188.1874
                                      Node  =  54.6255  2000.0
     q = 0.931432 AU                  Incl. =  41.1365


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

                         (C) Copyright 2015 CBAT
2015 November 5                  (CBET 4161)              Daniel W. E. Green