IAU Electronic Telegram No. 4538

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 P/2018 P1 = P/2010 A1 (HILL)
     E. Schwab, Egelsbach, Germany, reports his recovery of comet P/2010 A1
(cf. IAUCs 9104, 9107) on CCD images obtained by P. Ruiz on Aug. 10.2 UT with
a 1.0-m f/4.4 reflector at the European Space Agency's Optical Ground Station,
Tenerife, Spain; the comet shows a faint tail extending about 15" in p.a.
260 degrees.  M. Micheli reported confirming CCD astrometry from observations
obtained on Aug. 12.3 by F. Monteiro and five other observers with a 1.0-m
f/7 reflector at the Observatorio Astronomico do Sertao de Itaparica at
Nova Itacuruba, Brazil.

     2018 UT             R.A. (2000) Decl.       Mag.   Observer
     Aug. 10.18050    3 57 28.00   +17 38 53.3   19.0   Ruiz
          10.18502    3 57 28.54   +17 38 56.0   19.1     "
          10.18804    3 57 28.90   +17 38 57.6   19.0     "
          12.29450    4 01 41.51   +17 58 57.9   20.7   Monteiro
          12.29700    4 01 41.82   +17 58 59.3   19.6     "
          12.29947    4 01 42.11   +17 59 00.7   20.6     "

     The indicated correction to the prediction by B. G. Marsden on MPC 94681
is Delta(T) = +0.39 day.  The following linked orbital elements by G. V.
Williams (from 150 observations spanning 2010 Jan. 6-2018 Aug. 12; mean
residual 0".6) and an ephemeris appear on MPEC 2018-P80.

                    Epoch = 2018 Oct.  9.0 TT
     T = 2018 Oct. 15.15907 TT        Peri. =  13.28370
     e = 0.5542467                    Node  =  47.32113 2000.0
     q = 1.9571781 AU                 Incl. =  10.30827
       a =  4.3907202 AU   n = 0.10712737   P =   9.20 years


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2018 CBAT
2018 August 13                   (CBET 4538)              Daniel W. E. Green