Electronic Telegram No. 3489 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 2013bn A. J. Drake, S. G. Djorgovski, M. J. Graham, A. Mahabal, and R. Williams, California Institute of Technology; J. L. Prieto, Princeton University; M. Catelan, Pontificia Universidad Catolica de Chile; S. M. Larson and E. Christensen, Lunar and Planetary Laboratory, University of Arizona; and R. H. McNaught, Australian National University, report the Catalina Real-time Transient Survey discovery of an apparent supernova in unfiltered CCD images: SN 2013 UT R.A. (2000.0) Decl. Mag. 2013bn Apr. 15.34 11 48 02.03 +54 34 38.6 17.9 L. Tomasella, S. Benetti, A. Pastorello, E. Cappellaro, M. Turatto, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that optical spectroscopy (range 340-820 nm; resolution 1.3 nm), obtained on Apr. 18.10 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC), shows that 2013bn is a type-Ic hypernova very similar to SN 1998bw at about 10 days after maximum light. The redshift of the host galaxy is about 0.0545 as measured from narrow H_alpha, [O III], and H_beta interstellar emission lines. The Asiago classification spectra are posted at website URL http://graspa.oapd.inaf.it; classification was made via GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383) and SNID (Blondin and Tonry 2007, Ap.J. 666, 1024). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2013 CBAT 2013 April 24 (CBET 3489) Daniel W. E. Green