Electronic Telegram No. 2761 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 2011dz IN UGC 10273 = PSN J16124482+2817032 Denis Vida, on behalf of the "La Sagra Sky Survey" (LSSS) Supernova Search Team" (which also includes Filip Novoselnik, Ivica Skokic, David Gostinski, Robert Gregic, Salvador Sanchez, Jaime Nomen, Reiner Stoss, Bill Yeung, Juan Rodriguez and Miguel Hurtado), report the discovery of an apparent supernova (red magnitude 16.4) on three CCD images (limiting mag about 20.0) taken on June 26.946, 26.956, and 26.967 UT with a 0.45-m telescope. The new object is located at R.A. = 16h12m44s.82, Decl = +28d17'03".2 (equinox 2000.0), which is 0".2 east and 4".8 south of the nucleus of the presumed host galaxy, UGC 10273. The variable was designated PSN J16124482+2817032 when posted at the Central Bureau's TOCP webpage and is here designated SN 2011dz based on the spectroscopic report below. Additional approximate magnitudes for 2011dz supplied by Vida, from unfiltered images LSSS unless otherwise noted: 1989 May 3.293, [22 (Digitized Sky Survey, red plate); 2010 May 19.979, [20 (LSSS); 20.954, [20 (LSSS); 2011 April 2.035, [20 (LSSS); June 27.883, 16.4 (LSSS, red). All LSSS images from 2010 May to 2011 June have been posted (with the red DSS image on the right) at the following website URL: http://img89.imageshack.us/img89/1737/ugc10273archive.png; the June 26 images are posted at http://img819.imageshack.us/img819/3272/ugc10273candidate.png. D. D. Balam, Dominion Astrophysical Observatory, National Research Council of Canada (NRCC); M. L. Graham, Las Cumbres Observatory Global Telescope, University of California at Santa Barbara; E. Y. Hsiao, Lawrence Berkeley Laboratory; and D. W. E. Green, Harvard University, report that a spectrogram (range 389-725 nm, resolution 0.3 nm) of PSN J16124482+2817032 = SN 2011dz, obtained on July 5.37 UT with the 1.82-m Plaskett Telescope of the NRCC, shows it to be a type-Ia supernova about 35 days past maximum light. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2011dz is most similar to the type-Ia supernova 2002ic at 35 days past 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 July 6 (CBET 2761) Daniel W. E. Green