Electronic Telegram No. 2748 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 2011dp IN PGC 6447 = PSN J01452477-0349353 L. A. G. Monard, Pretoria, South Africa, reports his discovery of an apparent supernova (mag 16.1) on unfiltered CCD images taken at the Klein Karoo Observatory on June 2.184 UT; the new object is located at R.A. = 1h45m24s.77, Decl. = -3d49'35".3 (equinox 2000.0), which is 11" west and 3" north of the core of the SBbc-type galaxy MCG -1-5-31 = PGC 6447. Nothing is visible at this position in Digitized Sky Survey images (limiting red mag 20.5). The variable was designated PSN J01452477-0349353 when posted at the Central Bureau's TOCP webpage and is here designated SN 2011dp based on the spectroscopic confirmation reported below. Additional approximate magnitudes for 2011dp: 2010 Sept. 8.09, [18.8 (Monard); 2011 June 3.166, 16.0 (Monard); 3.817, 16.1 (Joseph Brimacombe, Coral Towers Observatory, Cairns, Australia, 30-cm reflector + STL6K camera; position end figures 24s.72, 34".7). Brimacombe's image is posted at the following website URL: http://www.flickr.com/photos/43846774@N02/5794676259/in/photostream. S. Valenti and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, on behalf of a larger collaboration, report that a spectrogram (range 330-750 nm; resolution 1.5 nm) of PSN J01452477-0349353 = SN 2011dp, obtained on June 25.38 UT with the European Southern Observatory's New Technology Telescope (+ EFOSC), is that of a type-Ia supernova. After cross-correlation with a library of supernova spectra via the "GELATO" code (Harutyunyan et al. 2008, A.Ap. 488, 383; available at website URL https://gelato.tng.iac.es/login.cgi), the spectrum of 2011dp appears to be very similar to that of SN 2003du (Stanishev et al. 2007, A.Ap. 469, 645) at 52 days after maximum light. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 June 26 (CBET 2748) Daniel W. E. Green