[IAUC] CBET 4244: 20160124 : COMET P/2016 A7 (PANSTARRS)

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 4244
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
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Prepared using the Tamkin Foundation Computer Network


COMET P/2016 A7 (PANSTARRS)
[Editor's note:  This text replaces that on CBET 4241 (missing report)]
     E. Lilly, R. Weryk, and R. Wainscoat, Institute for Astronomy, University
of Hawaii, report the discovery of an apparent comet in four w-band exposures
taken on Jan. 14.7 UT with the 1.8-m Pan-STARRS1 telescope on Haleakala
(discovery observations tabulated below); the object has a marginally fuzzy
appearance.

     2016 UT             R.A. (2000) Decl.       Mag.
     Jan. 14.65357   14 36 53.99   -21 51 38.3   21.5
          14.65550   14 36 54.23   -21 51 38.8   21.5
          14.65744   14 36 54.43   -21 51 39.4   21.8
          14.65937   14 36 54.68   -21 51 39.9   21.5

After the object was posted on the Minor Planet Center's PCCP webpage, H.
Sato (Tokyo, Japan) writes that twelve stacked 60-s exposures taken with an
iTelescope 0.51-m f/6.8 astrograph (+ luminance filter) at Siding Spring on
Jan. 18.7 UT show the object to be strongly condensed with an outer coma 12"
in diameter (with w-band 18.9 as measured within a circular aperture of
radius 6".6), and no tail was detected.  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
Jan. 22.5 show that the object has a fuzzy appearance compared to field
stars of similar magnitude; the comet's magnitude was measured as 20.7-21.1.
     The available astrometry (spanning Jan. 14-22), the following preliminary
elliptical orbital elements by G. V. Williams, and an ephemeris appear on MPEC
2016-B62.

     T = 2016 Apr.  6.9156 TT         Peri. =   8.9130
     e = 0.190896                     Node  = 218.1219  2000.0
     q = 1.985129 AU                  Incl. =  17.2772
       a =  2.453489 AU    n = 0.2564649    P =   3.84 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2016 CBAT
2016 January 24                  (CBET 4244)              Daniel W. E. Green