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Back Circular No. 9000 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://www.cfa.harvard.edu/iau/cbat.html ISSN 0081-0304 Phone 617-495-7440/7244/7444 (for emergency use only) COMET P/2008 U1 = P/2000 S7 (McMILLAN) S. Nakano, Sumoto, Japan, reports his identification of two nights of previously unpublished observations (here designated P/2000 S7), obtained with the Lowell Observatory 0.59-m Schmidt telescope in the course of the LONEOS project (astrometry given below), with comet P/2008 U1 (cf. IAUC 8997). 2000 UT R.A. (2000) Decl. Mag. Sept.23.20248 23 09 38.53 - 9 03 32.6 18.1 23.21798 23 09 37.84 - 9 03 39.7 23.23342 23 09 37.45 - 9 03 43.4 23.24886 23 09 36.96 - 9 03 50.6 Oct. 2.18685 23 05 32.41 - 9 50 41.0 18.3 2.20628 23 05 32.03 - 9 50 44.1 2.22565 23 05 31.36 - 9 50 51.9 2.24506 23 05 31.00 - 9 50 57.4 These observations required a correction of Delta(T) = +1.19 days in 2000 from an orbit utilizing astrometry from 2008 Sept. 20-Nov. 21. Nakano provides the following orbital elements linking 103 observations, 2000-2008 (mean residual 0".66). The comet passed 0.18 AU from Jupiter in 2004 July 8. Epoch = 2000 Dec. 2.0 TT T = 2000 Dec. 8.9745 TT Peri. = 217.3768 e = 0.350672 Node = 152.9971 2000.0 q = 2.693367 AU Incl. = 7.1433 a = 4.147928 AU n = 0.1166695 P = 8.45 years Epoch = 2008 May 14.0 TT T = 2008 May 13.2573 TT Peri. = 310.4836 e = 0.374407 Node = 36.4178 2000.0 q = 2.524827 AU Incl. = 4.4128 a = 4.035895 AU n = 0.1215610 P = 8.11 years COMET C/2006 W3 (CHRISTENSEN) Visual total-magnitude estimates: Sept. 7.81 UT, 10.4 (K. Yoshimoto, Yamaguchi, Japan, 25-cm reflector); Oct. 18.81, 10.5 (A. Diepvens, Balen, Belgium, 15-cm refr.); Nov. 16.74, 10.3 (B. Granslo, Fjellhamar, Norway, 20-cm refl.); 30.80, 10.0 (M. Meyer, Limburg, Germany, 15-cm refr.). (C) Copyright 2008 CBAT 2008 December 4 (9000) Daniel W. E. Green