Electronic Telegram No. 2218 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 SUPERNOVAE 2010av AND 2010aw Further to CBET 2211, A. Narla, J. Rex, S. B. Cenko, W. Li, and A. V. Filippenko, University of California, report the LOSS discovery of two apparent supernovae on unfiltered KAIT images: SN 2010 UT R.A. (2000.0) Decl. Mag. Offset 2010av Mar. 19.44 15 06 57.01 +56 30 27.8 17.9 18".6 E, 5".9 S 2010aw Mar. 19.54 17 16 12.28 +31 47 36.4 18.3 19".0 E, 3".1 N Additional KAIT magnitudes for 2010av in IC 1099: 2010 Feb. 14.59 UT, [19.3; Mar. 20.48, 17.9. Additional KAIT magnitudes for 2010aw in UGC 10781: a co-added image from exposures taken during 2009 Sept. 4-Oct. 3, [19.5; 2010 Mar. 20.51, 18.1. J. M. Silverman, I. K. W. Kleiser, A. J. L. Morton, and A. V. Filippenko, University of California, Berkeley, report that inspection of CCD spectra (range 340-1000 nm), obtained on Mar. 22 UT with the 3-m Shane reflector (+ Kast) at Lick Observatory, shows that 2010av is likely a type-Ib/c supernova. Cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2010av is a few days past maximum light and that the most likely redshift is about 0.04. However, narrow emission lines from the host galaxy are present in the spectrum at redshift 0.029. SN 2010aw is a young type-II supernova; the H-alpha emission greatly dominates over the absorption component. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 March 23 (CBET 2218) Daniel W. E. Green