Electronic Telegram No. 2740 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 2011dj IN PGC 45427 = PSN J13070669-0110440 A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams, California Institute of Technology; J. L. Prieto, Carnegie Observatories; M. Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the Catalina Real-time Transient Survey's discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images, as tabulated below. The variable was designated PSN J13070669-0110440 when posted on the Central Bureau's TOCP webpage and is here designated SN 2011dj based on the spectroscopic report below. SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011dj June 4.21 13 07 06.69 - 1 10 44.0 15.8 15".7 E, 7".2 S Additional CCD magnitudes for 2011dj: May 25.28 UT, [20.0 (CSS); June 4.563, R = 15.7 (Joseph Brimacombe, Coral Towers Observatory, Cairns, Australia; 30-cm reflector + STL6K camera; five 600-s stacked images; position end figures 06s.67, 45".5); 7.567, R = 15.1 (S. Baroni, L. Buzzi, P. Concari, S. Foglia, G. Galli, and M. Tombelli; remotely using a 0.18-m f/2.8 reflector at the Tzec Maun Observatory, Moorook, Australia; position end figures 06s.69, 45".0); 9.424, R = 15.4 (Baroni et al.). Foglia adds that nothing is visible at the position of 2011dj in NEAT images from 2002 Apr. 14 and 2003 Apr. 9 (no limiting magnitudes provided). Brimacombe's image is posted at website URL http://www.flickr.com/photos/43846774@N02/5799770906/. Foglia notes that their image from June 7 is posted at the following website URL: URL http://www.apan.it/pianetini/pub/psn/pgc45427.htm. L. Tomasella, P. Ochner, S. Valenti, and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 390-810 nm; resolution 2.2 nm) of PSN J13070669-0110440 = SN 2011dj, obtained on June 6.87 UT with the Ekar-Copernicus 1.82-m telescope (+ AFOSC), shows it to be a type-Ia supernova, a couple of days before maximum. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 June 10 (CBET 2740) Daniel W. E. Green