Electronic Telegram No. 2246 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Room 209; Dept. of Earth and Planetary Sciences; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbat@iau.org; cbatiau@eps.harvard.edu URL http://www.cfa.harvard.edu/iau/cbat.html COMET C/2010 G3 (WISE) A. Mainzer, Jet Propulsion Laboratory, reports the discovery by WISE of a comet candidate (discovery position below), about as bright as C/2010 D1 (IAUC 9118) at 12 microns and having about twice the 12-micron SNR at 22 microns, making it easily the brightest WISE discovery in the latter band. The coma is 25" in diameter at 12 microns and about 40" in diameter with a 20" tail at 22 microns. W. H. Ryan, observing with the 2.4-m reflector at Magdalena Ridge on Apr. 16.3 UT, puts the comet at R magnitude 18.4-18.6 and remarks on a distinct coma and a tail in p.a. 170 deg. 2010 UT R.A. (2000) Decl. Observer Apr. 14.13821 18 48 36.28 +47 28 03.3 WISE Further astrometry, the following very preliminary parabolic orbital elements and an ephemeris are given on MPEC 2010-H04. T = 2010 Sept. 26.597 TT Peri. = 98.838 Node = 316.408 2000.0 q = 4.66346 AU Incl. = 109.045 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 April 16 (CBET 2246) Brian G. Marsden