Electronic Telegram No. 2636 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network SUPERNOVA 2011K A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams, California Institute of Technology; J. L. Prieto, Carnegie Observatories; M. Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the Catalina Real-time Transient Survey's discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011K Jan. 13.19 4 45 30.38 - 7 20 52.7 15.1 2" S Nothing is visible at this position on a CSS image from 2010 Dec. 10.32 UT (limiting mag 19.0). After posting on the "Transient Object Confirmation Page", R. A. Koff (Antelope Hills Observatory, Colorado) reports that thirteen images obtained around Jan. 14.069 UT reveal mag 15.1 and position end figures 30s.38, 53".2 for 2011K. K. Ayani, Bisei Astronomical Observatory (BAO); and H. Yamaoka, Kyushu University, report that low-resolution spectra (range 400-750 nm; resolution 0.6 nm at H-alpha) of 2011K were obtained with the BAO 1.01-m telescope on Jan. 13.6 UT. The spectra show that 2011K is a type-Ia supernova, several days before maximum. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 January 14 (CBET 2636) Daniel W. E. Green