IAU Electronic Telegram No. 4510

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 H1 = P/2011 CR42 (CATALINA)
     E. Schwab, Egelsbach, Germany, reports his recovery of this comet (cf.
CBETs 2823, 3684) on CCD images that he took remotely with the 0.8-m f/3
Schmidt reflector at Calar Alto, Spain (astrometry tabulated below;
measuring assistance by D. Koschny and M. Micheli).  On each of the two
nights, total exposure times of 600 s revealed no coma or tail.

     2018 UT             R.A. (2000) Decl.       Mag.   Observer
     Apr. 17.01417   14 31 15.72   - 8 41 42.5   21.0   Schwab
          17.02370   14 31 15.30   - 8 41 42.4   20.9     "
          17.03335   14 31 14.84   - 8 41 42.1   21.0     "
          17.07509   14 31 12.93   - 8 41 40.4   21.1     "
          18.04705   14 30 30.41   - 8 41 09.0   20.9     "
          18.06811   14 30 29.47   - 8 41 08.6   20.8     "
          18.07853   14 30 29.01   - 8 41 08.2   21.2     "

The indicated correction to the predictions by G. V. Williams on MPEC 2013-Y32
and by S. Nakano in the ICQ's 2018 Comet Handbook is Delta(T) = -0.25 day.
The following linked orbital elements by G. V. Williams (from 121 observations
spanning 2011 Feb. 10-2018 Apr. 18) and an ephemeris appear on MPEC 2018-H30.

                    Epoch = 2018 June 11.0 TT
     T = 2018 June 22.32531 TT        Peri. = 173.11469
     e = 0.2814492                    Node  =  58.72174 2000.0
     q = 2.5217202 AU                 Incl. =   8.46465
       a =  3.5094527 AU   n = 0.14991496   P =   6.57 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2018 CBAT
2018 April 18                    (CBET 4510)              Daniel W. E. Green