Electronic Telegram No. 4162
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 C/2015 V3 (PANSTARRS)
     R. Weryk, R. Wainscoat, and E. Lilly report the discovery of an possible
comet in four w-band exposures taken on Nov. 2.6 UT with the 1.8-m Pan-STARRS1
telescope on Haleakala (discovery observations tabulated below), in which the
object's FWHM (1".3) is slightly larger than that of adjacent stars (0".9) in
a three-frame stack, and there is evidence of a very faint tail extending
towards position angle approximately 60 degrees for approximately 4".

     2015 UT             R.A. (2000) Decl.       Mag.
     Nov.  2.27229   23 37 01.08   - 6 09 13.2   21.8
           2.28344   23 37 00.36   - 6 09 08.9   21.7
           2.29462   23 36 59.73   - 6 09 03.9   21.4
           2.30579   23 36 59.07   - 6 08 59.3   21.5

M. Micheli and Wainscoat add that three 60-s confirming exposures were
obtained by Wainscoat and C. Wipper with the 3.6-m Canada-France-Hawaii
Telescope at Mauna Kea on Nov. 5.2 UT, showing that the object has a diffuse
appearance and displays an obvious coma (FWHM 2".0) elongated to the east; the
red magnitude was measured to be 20.8-20.9.
     After the object was posted on the Minor Planet Center's PCCP webpage,
other CCD astrometrists have also noted the object's cometary appearance.
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. 6.14-6.16 UT show a distinct coma
of magnitude 20.4-20.8.  H. Sato, Tokyo, Japan, relates that six stacked 60-s
exposures taken on Nov. 6.44-6.45 with a 0.51-m f/6.8 astrograph (+ luminance
filter) at Siding Spring show the comet to be moderately condensed with a coma
8" in diameter, with a suspected 20" tail toward p.a. 275 degrees; the w-band
magnitude was 20.0 as measured within a circular aperture of radius 6".6.
     The available astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2015-V60.

     T = 2015 Nov.  1.0046 TT         Peri. = 357.0140
                                      Node  =   2.3083  2000.0
     q = 4.244900 AU                  Incl. =  86.6544


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 November 6                  (CBET 4162)              Daniel W. E. Green