Electronic Telegram No. 3359 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 2012ib IN UGC 9684 = PSN J15035487+4206553 V. Lipunov, Sternberg Astronomical Institute (SAI), reports the discovery by V. Shumkov of an apparent supernova (magnitude 16.0) on four 60-sec unfiltered survey images from the MASTER-Amur robotic telescope (0.40-m f/2.5 reflector) taken between Dec. 20.807 and 20.838 UT. D. Denisenko and E. Gorbovskoy (SAI) report that the new object is located at R.A. = 15h03m54s.87, Decl. = +42d06'55".3 (equinox 2000.0), which is 48".7 east and 0".4 south of the nucleus of UGC 9684. Nothing is visible at this position on MASTER-Amur images from Nov. 29 (limiting magnitude 17.7) or on archival Digitized Sky Survey plates or a Sloan Digital Sky Survey image of the field. A comparison of the discovery and reference images is posted at website URL http://master.sai.msu.ru/static/OT/150354.87420655.3.png. The variable was designated PSN J15035487+4206553 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012ib based on the spectroscopic confirmation reported below. The type-II supernova 2006ed also appeared in UGC 9684 (cf. IAUC 8741). Additional CCD magnitudes for 2012ib: Dec. 15.791 and 15.855, 16.3 (MASTER-Amur telescope; marginally visible near the limiting magnitude); 22.526, 16.7 (J. Brimacombe, Cairns, Australia; remotely with a 51-cm RCOS telescope + luminance filter at the New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end figures 54s.86, 56".0; image posted at URL http://www.flickr.com/photos/43846774@N02/8304717075/). L. Tomasella, S. Benetti, E. Cappellaro, P. Ochner, A. Pastorello, and M. Turatto, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that optical spectroscopy (range 340-820 nm; resolution 1.3 nm), obtained on Dec. 23.10 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC), shows that PSN J15035487+4206553 = SN 2012ib is characterized by features that are typical of stripped-envelope supernovae. Adopting for the host galaxy (UGC 9684) a redshift z = 0.016872 (Bottinelli et al. 1993, A.Ap. Suppl. 102, 57; via NED), the best match was found with various type-Ib/c supernovae at some days past maximum. The Asiago classification spectra are posted at website URL http://graspa.oapd.inaf.it; classification was made via GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383) and SNID (Blondin and Tonry 2007, Ap.J. 666, 1024). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2012 CBAT 2012 December 26 (CBET 3359) Daniel W. E. Green