Electronic Telegram No. 3561 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 2013dh IN NGC 5936 = PSN J15300109+1259129 Further to CBET 3422, S. Kumar, K. Fuller, W. Zheng, S. B. Cenko, W. Li, and A. V. Filippenko report the LOSS discovery of an apparent supernova on unfiltered KAIT images: SN 2013 UT R.A. (2000.0) Decl. Mag. Offset 2013dh June 12.33 15 30 01.09 +12 59 12.9 18.0 3".7 E, 8".6 N The variable was designated PSN J15300109+1259129 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2013dh based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2013dh: June 9.35 UT, [18.5 (KAIT); 12.931, 16.5 (S. Foglia and G. Galli, Pogliano Milanese, Italy; 0.28-m Schmidt-Cassegrain reflector + ST8XME camera; UCAC-4 reference stars; position end figures 01s.11, 12".8); 13.593, 18.4 (Joseph Brimacombe, Cairns, Australia; 41-cm telescope + infrared filter; bandpass > 700 nm; position end figures 01s.09, 13".0; image posted at website URL http://www.flickr.com/photos/43846774@N02/9043487561/). S. B. Cenko, Goddard Space Flight Center, NASA; B. E. Tucker, Australian National University; and I. Shivvers, K. I. Clubb, and A. V. Filippenko, University of California, Berkeley, report that inspection of a CCD spectrum (range 350-1000 nm), obtained on June 14.3 UT with the Shane 3-m reflector (+ Kast spectrograph) at Lick Observatory, shows that PSN J15300109+1259129 = SN 2013dh is a type-Ia supernova. Cross-correlation with a library of supernova spectra using the "SuperNova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates a similarity with pre-maximum-light spectra of SN 1991T (Filippenko et al. 1992, Ap.J. 384, L15), with a blue continuum and relatively weak Si II 635.5-nm absorption. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2013 CBAT 2013 June 16 (CBET 3561) Daniel W. E. Green