Electronic Telegram No. 2696 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 2011bn = PSN J16164236+0014299 S. Howerton, Arkansas City, KS, U.S.A.; 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 discovery via the Catalina Real-time Transient Survey (CRTS) of an apparent supernova in public images from the Catalina Sky Survey (CSS). This variable was designated PSN J16164236+0014299 when posted on the Central Bureau's TOCP webpage and is here designated SN 2011bn based on the spectroscopic confirmation reported below. SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011bn Mar. 8.46 16 16 42.36 + 0 14 29.9 18.9 17".9 W, 16".9 S Further unfiltered CCD magnitudes for 2011bn: Feb. 11.52 UT, [19.7 (CSS); Mar. 9.50, 17.9 (remotely using a 0.5-m LB-1 telescope near Rodeo, NM, U.S.A., by the CRTS team); 10.430, 18.0 (Joseph Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K camera at New Mexico Skies Observatory, Mayhill, NM, U.S.A.; position end figures 42s.54, 28".6). Brimacombe has posted his image at the following website URL: http://www.flickr.com/photos/43846774@N02/5515332321/. L. Tomasella and S. Benetti, Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Padova; and F. Bufano, INAF, Osservatorio Astronomico di Catania, on behalf of a larger collaboration, report that a spectrum of 2011bn = PSN J16164236+0014299, obtained on Apr. 10.41 UT with the New Technology Telescope (+ EFOSC2; range 340-750 nm, resolution 1.3 nm), shows it to be a type-II supernova. The best fits to this noisy spectrum found by GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383; publicly available at https://gelato.tng.iac.es) are with spectra of type-II supernovae at about one month post explosion, adopting a recession velocity of 9183 km/s for UGC 10306 (Bottinelli et al. 1993, A.Ap. 102, 57; via NED). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 April 12 (CBET 2696) Daniel W. E. Green