Electronic Telegram No. 3180 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 2012dp IN IC 1155 = PSN J16003509+1541043 S. Howerton, Arkansas City, KS, U.S.A.; A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams, California Institute of Technology; J. L. Prieto, Princeton University; M. Catelan, Pontificia Universidad Catolica de Chile; R. H. McNaught, Australian National University; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the discovery of an apparent supernova in public images from the Catalina Sky Survey (CSS). SN 2012 UT R.A. (2000.0) Decl. Mag. Offset 2012dp June 16.32 16 00 35.09 +15 41 04.3 19.5 9".7 W, 3".9 S The variable was designated PSN J16003509+1541043 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012dp based on the spectroscopic confirmation reported below. Additional magnitudes for 2012dp: May 25.28 UT, [20.5 (CSS); June 10.29, 20.1 (CSS); 18.323, 17.8 (Joseph Brimacombe, Cairns, Australia, remotely using a 51-cm RCOS telescope + STL11K camera + luminance filter at the New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end figures 35s.17, 03".5; image posted at website URL http://www.flickr.com/photos/43846774@N02/7398233902/); 22.008, 18.2 (Xavier Bros, Anysllum Observatory, Ager, Spain; position end figures 35s.25, 04".7; image posted at website URL http://tinyurl.com/89np2m8). L. Tomasella, S. Benetti, E. Cappellaro, P. Ochner, A. Pastorello, M. Turatto, and S. Valenti, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that a noisy spectrogram of PSN J16003509+1541043 = 2012dp, obtained on July 16.95 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 340-820 nm; resolution 2.4 nm), suggests that it is a type-Ib supernova. Cross-correlation with a library of supernova spectra via the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2012dp is similar to several normal type-Ib supernovae not far from maximum at a redshift about 0.038 (in agreement with that reported for the presumed host galaxy by Haynes et al. 1997, A.J. 113, 119; via NED). The spectrum is dominated by a broad P-Cyg line centered at about 600 nm. If it is assumed as due to the He I 587.6-nm transition from its minimum, an expansion velocity of about 8800 km/s is derived for the ejecta. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2012 CBAT 2012 July 18 (CBET 3180) Daniel W. E. Green