Electronic Telegram No. 438 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 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://cfa-www.harvard.edu/iau/cbat.html COMET C/2006 F1 (KOWALSKI) R. A. Kowalski reports the discovery of a comet on CCD images taken in poor seeing (4" FWHM) with the 1.5-m reflector in the course of the Mt. Lemmon Survey (discovery observation tabulated below); the object appeared slightly condensed with a diameter of approximately 8", elongated in p.a. approximately p.a. 265 deg (though no obvious tail). On images taken with the same telescope by E. J. Christensen on Mar. 23.5 UT, the object displays a diffuse, round 8" coma and a 10" tail in p.a. about 245 degrees. CCD images taken by P. Birtwhistle with a 0.40-m f/6 Schmidt-Cassegrain reflector at Great Shefford, U.K., on Mar. 23.1 show the object with a 8" coma and a tail 15" long in p.a. 245 deg. 2006 UT R.A. (2000) Decl. Mag. Mar. 21.49155 16 21 29.96 + 2 00 22.3 18.8 The available astrometry, the following parabolic orbital elements, and an ephemeris appear on MPEC 2006-F20. T = 2007 May 19.709 TT Peri. = 208.890 Node = 124.985 2000.0 q = 1.93896 AU Incl. = 21.585 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2006 CBAT 2006 March 23 (CBET 438) Daniel W. E. Green