Electronic Telegram No. 2752 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 2011dt IN UGC 9233 = PSN J14243612+3516387 Further to CBET 2721, M. Kandrashoff, S. B. Cenko, W. Li, and A. V. Filippenko report the LOSS discovery of an apparent supernova on unfiltered KAIT images. The object was designated PSN J14243612+3516387 when posted on the Central Bureau's TOCP webpage and is here designated SN 2011dt based on the spectroscopic confirmation reported below. SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011dt June 8.30 14 24 36.12 +35 16 38.7 18.6 14".3 E, 9".0 S Additional CCD magnitudes (unfiltered unless noted otherwise) for 2011dt: 2010 May 30.30 UT, [19.6 (KAIT); 2011 June 9.26, 18.7 (KAIT); 10.168, 17.9 (Joseph Brimacombe, Cairns, Australia; position end figures 36s.14, 38".6); 13.40, 19.2 (P. Miller, P. Roche, A. Tripp, R. Miles, R. Holmes, S. Foglia, and L. Buzzi, 2.0-m f/10 "Faulkes Telescope North" + Bessel R filter, at Haleakala, Hawaii, in 1".2 seeing; position end figures 36s.16, 38".8); 25.958, 17.8 (Xavier Bros, Ager, Catalonia, Spain, 35-cm telescope + ST8XME camera; position end figures 36s.03, 39".2). Brimacombe's image is posted at website URL http://www.flickr.com/photos/43846774@N02/5819582576/. Miller et al. posted their image at http://www.apan.it/pianetini/pub/psn/PSN-UGC9233.jpg. Bros' image is posted at http://anysllum.com/SNUGC9233.jpg. J. M. Silverman and A. V. Filippenko, University of California, Berkeley, report that inspection of a CCD spectrum (range 340-1000 nm), obtained by J.-H. Woo, H.-J. Bae, D. Park, and D. Son (Seoul National University) on June 10 UT with the 3-m Shane reflector (+ Kast) at Lick Observatory, shows that PSN J14243612+3516387 = SN 2011dt is a young type-II supernova with a relatively blue continuum. After removal of the host-galaxy recession velocity of 8300 km/s, determined from narrow emission lines, the absorption minimum of the H-alpha line (which is greatly dominated by the emission component) is found to be blueshifted by 7900 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 June 30 (CBET 2752) Daniel W. E. Green