Electronic Telegram No. 4107
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; 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 P/2015 K3 = P/2010 R2 (LA SAGRA)
     Comet P/2010 R2 (cf. IAUC 9169) has been observed over three nights
as it nears perihelion later this year, in March and April via CCD images
obtained by S. S. Sheppard with the Magellan-Baade telescope (measured by
M. Micheli and H. H. Hsieh), and this month via images taken by J. V. Scotti
with the Spacewatch 1.8-m telescope at Kitt Peak (ten stacked 60-s exposures
show a stellar appearance).  The report by Scotti arrived before the report
from Micheli.  The astrometry is tabulated below.

     2015 UT             R.A. (2000) Decl.       Mag.   Observer
     Mar. 21.40571   19 21 19.01   -22 44 03.0   22.8   Sheppard
          21.41005   19 21 19.35   -22 44 01.3   22.6     "
     Apr. 18.39658   19 50 33.27   -19 13 50.2   22.5     "
          18.40222   19 50 33.54   -19 13 47.4   22.4     "
          18.40784   19 50 33.82   -19 13 44.8   22.6     "
     May  22.42872   20 06 28.00   -14 21 58.8   21.6   Scotti
          22.43625   20 06 28.00   -14 21 54.6   21.9     "
          22.44381   20 06 28.05   -14 21 50.2   22.7     "

The indicated correction to the prediction by S. Nakano in the ICQ's 2014
Comet Handbook is Delta(T) = -0.03 day.  The following linked orbital
elements by G. V. Williams and an ephemeris appear on MPEC 2015-K101.

                    Epoch = 2015 Dec.  4.0 TT
     T = 2015 Nov. 29.90222 TT        Peri. =  58.55676
     e = 0.1537768                    Node  = 270.65011 2000.0
     q = 2.6198415 AU                 Incl. =  21.41643
       a =  3.0959226 AU   n = 0.18093348   P =   5.45 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 May 26                      (CBET 4107)              Daniel W. E. Green