Electronic Telegram No. 2732 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 2011dg IN IC 4523 = PSN J15050910-4330462 G. Pignata and M. Cifuentes, Universidad Andres Bello; J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, R. Cartier, F. Forster, S. Silva, F. Carrasco, P. Sanchez, C. Hervias, D. Iturra, and R. Ramirez, Universidad de Chile; C. Farias, Pontificia Universidad Catolica de Chile; B. Conuel, Wesleyan University; G. Folatelli, IPMU, University of Tokyo; and D. Reichart, K. Ivarsen, J. Haislip, A. Crain, D. Foster, M. Nysewander, and A. LaCluyze, University of North Carolina at Chapel Hill, on behalf of the CHASE project (which is part of the Millennium Center for Supernova Science collaboration), report the discovery of an apparent supernova (mag approximately 17.0) on an unfiltered image taken on May 18.24 UT with the 0.41-m 'PROMPT 1' telescope located at Cerro Tololo. The new object (which was designated PSN J15050910-4330462 when posted on the Central Bureau's TOCP webpage and is here designated SN 2011dg based on the spectroscopic report below) is located at R.A. = 15h05m09s.10 +/- 0".2, Decl. = -43o30'46".2 +/- 0".2 (equinox 2000.0), which is about 15".5 west and 12".4 south of the center of the galaxy IC 4523. Additional CCD magnitudes for 2011dg: 2010 Apr. 13.24, [18.5 (CHASE); 2011 May 7.11, [17.0 (CHASE); 19.00, 16.4 (CHASE); 22.666, 17.2 (Joseph Brimacombe, Coral Towers Observatory, Cairns, Australia, 30-cm reflector + STL6K camera + red filter; ten 600-s stacked images; position end figures 09s.12, 45".9). Brimacombe's image is posted at the following website URL: http://www.flickr.com/photos/43846774@N02/5748616071/. The type-IIP supernova 2010gh also appeared in IC 4523 (cf. CBETs 2372, 2390). M. Stritzinger, Oskar Klein Centre, Stockholm University, on behalf of the Millennium Center for Supernova Science, reports that he obtained a spectrogram on May 29.4 UT of PSN J15050910-4330462 = SN 2011dg with the Gemini-South telescope (+ GMOS). The spectrum of 2011dg is consistent with that of a normal type-IIP supernova at about two weeks past explosion. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 May 31 (CBET 2732) Daniel W. E. Green