C/2015 F3 SWAN

COMET C/2015 M3 (PANSTARRS)
     An apparently asteroidal object discovered on exposures taken with the
1.8-m Pan-STARRS1 telescope at Haleakala on June 29 UT (discovery observations
tabulated below) has been found to show cometary appearance by CCD
astrometrists elsewhere after the object was posted on the Minor Planet
Center's PCCP webpage.

     2015 UT             R.A. (2000) Decl.       Mag.
     June 29.42977   18 14 32.62   +50 21 27.8   20.1
          29.44334   18 14 31.99   +50 21 21.0   20.2
          29.47047   18 14 30.74   +50 21 07.0   20.0

H. Sato, Tokyo, Japan, obtained twelve 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, on July 7.26 UT that reveal a strongly
condensed coma 6" in diameter with a w-band magnitude of 19.0 as measured
within a circular aperture of radius 3".8; no tail was seen.  J. V. Scotti
writes that ten stacked 60-s exposures taken with the Spacewatch 1.8-m f/2.7
reflector at Kitt Peak on July 12.3 show the object to be very slightly
diffuse with a coma of diameter 6" and magnitude 19.5-19.6, elongated about
0'.10 toward p.a. 171 deg.
     The available astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2015-N47.

     T = 2015 Sept. 1.8289 TT         Peri. = 125.2447
                                      Node  = 142.6448  2000.0
     q = 3.563063 AU                  Incl. =  66.1933



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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 July 15                     (CBET 4118)              Daniel W. E. Green