Electronic Telegram No. 2737 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 2011di IN IC 4754 = PSN J18435900-6159460 L. A. G. Monard, Pretoria, South Africa, reports his discovery of an apparent supernova (mag 17.5) on several unfiltered CCD images obtained on May 13.005 UT at the Klein Karoo Observatory. The new object, which was designated PSN J18435900-6159460 when posted on the Central Bureau's TOCP webpage and is here designated SN 2011di based on the spectroscopic report below, is located at R.A. = 18h43m59s.06, Decl. = -61d59'46".3, which is 9" west and 21" south of the core of the SBb-type galaxy IC 4754; Monard notes that a faint star just south of the galaxy's core must somewhat affect the accuracy of the derived position. Nothing is visible at this position on Digitized Sky Survey images (limiting red mag 20.5) or on 2010 images taken at Monard's Bronberg Observatory (limiting mag 18.5 and fainter). Additional magnitudes for 2011di: 2011 Apr. 30.102, [18.8 (Monard); May 14.894, 16.5 (Monard); 15.134, 16.5 (Monard); 15.875, 16.2 (Monard); 17.880, 15.7 (Monard); 22.740, 14.8 (Joseph Brimacombe, Coral Towers Observatory, Cairns, Australia, 30-cm telescope + STL6K camera + red filter; position end figures 59s.12, 45".7); 23.725, 14.7 (Brimacombe); 24.658, 14.7 (Brimacombe); 25.756, 14.7 (Brimacombe). Brimacombe's May 22 image is posted at the following website URL: http://www.flickr.com/photos/43846774@N02/5748796850/. D. Milisavljevic and R. Fesen, Dartmouth College; K. Nordsieck, University of Wisconsin; and T. Pickering and D. O'Donoghue, South African Astronomical Observatory, on behalf of a larger SALT Commissioning Team, report that low- dispersion spectra (range 350-750 nm), obtained May 28 UT with the 10-m SALT telescope (+ RSS), show PSN J18435900-6159460 = SN 2011di to be 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) shows matches with normal type-Ia events at less than one week 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 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.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 5 (CBET 2737) Daniel W. E. Green