Electronic Telegram No. 3603
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/2013 O1 = P/1998 Y1 (LI)
     R. H. McNaught has suggested the identity with P/1998 Y2 (cf. IAUC 7075)
of a comet displaying a slightly diffuse circular coma of diamter about 12"
that he found on images taken with the 0.5-m Uppsala Schmidt telescope at
Siding Spring on July 24 and 26 -- an identification confirmed by G. V.
Williams, Minor Planet Center.  H. Sato (Tokyo, Japan) has identified nearly
stellar pre-recovery images of the comet on ten stacked 60-s exposures taken
on May 9.8 UT with a 0.51-m f/6.8 astrograph at Siding Spring (iTelescope.net).
T. Spahr identified apparently asteroidal observations reported by M. Masek
(Liberec, Czech Republic) on July 16.4 from exposures taken with a 0.3-m f/10
reflector located at Malargue,Mendoza, Argentina, and reported to the MPC.

     2013 UT             R.A. (2000) Decl.       Mag.   Observer
     May   9.79570    0 16 15.46   -20 01 16.5          Sato
           9.79866    0 16 15.66   -20 01 15.8   20.4     "
     July 16.38706    1 41 32.53   -18 36 54.6   19.7   Masek
          16.39420    1 41 32.88   -18 36 55.4   19.6     "
          16.40064    1 41 33.19   -18 36 56.2   20.1     "
          24.75334    1 49 43.09   -19 01 34.3   18.6   McNaught
          24.77779    1 49 44.49   -19 01 39.9   19.4     "
          26.73367    1 51 31.73   -19 08 43.2   18.7     "
          26.74206    1 51 32.22   -19 08 45.0   19.1     "
          26.75040    1 51 32.62   -19 08 46.9   19.1     "

The indicated correction to the prediction by S. Nakano on MPC 75730 is
Delta(T) = +0.85 day.  The following linked orbital elements by Williams are
from 49 observations spanning 1998 Sept. 23-2013 July 26 (mean residual 0".7):

                    Epoch = 2014 Jan. 23.0 TT
     T = 2014 Feb.  4.82821 TT        Peri. = 319.05802
     e = 0.5879150                    Node  =  91.86356 2000.0
     q = 2.5223583 AU                 Incl. =  24.35756
       a =  6.1209662 AU   n = 0.06508398   P =  15.14 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 July 27                     (CBET 3603)              Daniel W. E. Green