Electronic Telegram No. 4337
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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Prepared using the Tamkin Foundation Computer Network


COMET C/2016 X1 (LEMMON)
     An apparently asteroidal object discovered on survey images obtained at
Mount Lemmon by G. J. Leonard on Dec. 8 (discovery observations tabulated
below) has been found to show slight cometary appearance as reported by CCD
astrometrists elsewhere after the object was posted on the Minor Planet
Center's PCCP webpage.

     2016 UT             R.A. (2000) Decl.       Mag.   Observer
     Dec.  8.35740    4 32 24.95   +25 01 18.4   20.1   Leonard
           8.37305    4 32 24.64   +25 01 15.5   20.3     "
           8.37861    4 32 24.56   +25 01 15.3   20.0     "
           8.38290    4 32 24.43   +25 01 14.2   20.4     "

H. Sato, Tokyo, Japan, writes that sixteen stacked 60-s exposures taken on
Dec. 20.25-20.26 UT with a 0.61-m f/6.5 astrograph (+ luminance filter)
located at the Sierra Remote Observatory near Auberry, CA, USA, shows the
object to be moderately condensed with a coma 6" in diameter and a hint hint
of tail 10" long toward p.a. 225 degrees; the w-band magnitude was 20.6 as
measured within a circular aperture of radius 3".8.  G-band images taken by
W. H. Ryan and E. V. Ryan with the 2.4-m f/8.9 reflector at Magdalena Ridge
Observatory on Dec. 21.25-21.27 show the object at mag 20.1-20.2 with a
point-spread function consistently about 1.4-1.5 times that of nearby stars
of similar brightness.
     The available astrometry (including pre-discovery observations reported
by R. Weryk that were obtained with the 1.8-m Pan-STARRS1 telescope at
Haleakala on Nov. 26.5 UT, when the magnitude was found to be 21.1-21.4), the
following elliptical orbital elements by G. V. Williams, and an ephemeris
appear on MPEC 2016-Y34.

                    Epoch = 2019 Apr. 27.0 TT
     T = 2019 May   2.0109 TT         Peri. = 224.5701
     e = 0.992264                     Node  = 256.4108  2000.0
     q = 7.574622 AU                  Incl. =  26.5210


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2016 CBAT
2016 December 21                 (CBET 4337)              Daniel W. E. Green