Electronic Telegram No. 2060 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://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2009mc Further to CBET 2059, M. Catelan, Pontificia Universidad Catolica de Chile; A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham and R. Williams, California Institute of Technology; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the CRTS discovery of a supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2009 UT R.A. (2000.0) Decl. Mag. 2009mc Nov. 21.51 8 55 59.81 - 5 19 44.6 18.1 Further magnitudes for 2009mc: Oct. 27.52 UT, [19.5 (CSS); Nov. 24.54, 17.7 (S. Howerton, Arkansas City, KS, U.S.A., remotely using the 0.3-m LB-0003 telescope near Rodeo, NM, U.S.A.). A deep r-band image from 2006 Jan. 2 with the 3.6-m Canada-France-Hawaii Telescope telescope clearly shows a galaxy (of mag approx 22) at the location of 2009mc. A noisy spectrogram (range 380-900 nm) of 2009mc exhibiting clear, broad absorption features was obtained with the SMARTS 1.5-m telescope on 2009 Nov. 30.25; cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (Blondin and Tonry 2007, Ap.J. 666, 1024) shows 2009mc to be most similar to the type-Ia supernova 1996C at one week past maximum light. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 December 1 (CBET 2060) Daniel W. E. Green