Electronic Telegram No. 4222
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 XY_1 (LEMMON)
     An apparently asteroidal object discovered on CCD images obtained by
J. A. Johnson with the Mount Lemmon 1.5-m reflector on Dec. 4 (discovery
observations tabulated below) was given the minor-planet designation 2015 XY_1
when published on MPS 657469.

     2015 UT             R.A. (2000) Decl.       Mag.   Observer
     Dec.  4.51796    9 33 40.21   +32 10 14.1   20.4   Johnson
           4.52257    9 33 40.09   +32 10 14.8   20.4     "
           4.52716    9 33 40.00   +32 10 15.3   20.3     "
           4.53174    9 33 39.88   +32 10 16.0   20.0     "

Numerous 30-s Mt. Lemmon Survey images taken subsequently by E. J. Christensen
on Dec. 16.45-16.47 UT show the object (identified by Christensen with 2015
XY_1 apparently after finding it as a potential new discovery) with a coma of
size about 8" (and magnitude 19.7-20.0).
     The available astrometry (spanning Dec. 4-16), the following preliminary
parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC
2015-Y06.

     T = 2018 Mar. 30.3946 TT         Peri. = 193.2690
                                      Node  = 281.3383  2000.0
     q = 8.140146 AU                  Incl. = 149.0749


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 December 17                 (CBET 4222)              Daniel W. E. Green