Electronic Telegram No. 3334 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 2012hk = PSN J10411534+3733218 V. Lipunov, Sternberg Astronomical Institute (SAI), reports the discovery by P. Balanutsa of a possible supernova (mag 16.7) on two unfiltered images (limiting mag 18.3) taken on Nov. 20.742 and 20.774 UT with the MASTER-Amur robotic telescope (0.40-m f/2.5 reflector). The new object is located at R.A. = 10h41m15s.34, Decl. = +37d33'21".8 (equinox 2000.0), which is 17".7 west and 25".2 north of a nearby galaxy (PGC 2103473). D. Denisenko and E. Gorbovskoy (SAI) report that nothing is visible at this position on a MASTER-Amur survey image from Oct. 28.879 (limiting mag 18.4), or on fifteen digitized Palomar Observatory Sky Survey plates (to limiting mag about 21) or on a Sloan Digital Sky Survey color image (to limiting mag about 23). The discovery and reference images are posted at the following website URL: http://master.sai.msu.ru/static/OT/104115.34373321.8.png. The variable was designated PSN J10411534+3733218 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012hk based on the spectroscopic confirmation reported below. Three 300-s images (limiting mag about 19.3) obtained remotely with a 0.45-m f/2.8 telescope at the ISON-NM Observatory near Mayhill, NM, USA, on Nov. 27.396 by L. Elenin (Lyubertsy, Russia) and I. Molotov (Moscow, Russia) yield position end figures 15s.45 +/- 0".13, 23".3 +/- 0".11 (UCAC-4 reference stars) and unfiltered mag 17.8; their image is posted at http://spaceobs.org/images/TOCP/PSNJ10411534+3733218-20121127.png. 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. 5.19 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 350-820 nm; resolution 1.3 nm), shows that PSN J10411534+3733218 = SN 2012hk is a type-II supernova at redshift z = 0.023986 (Sloan Digital Sky Survey Data Release 5, 2006; via NED database) or a supernova impostor. The low-signal-to-noise spectrum shows narrow H_alpha in emission (with a FWHM velocity of about 700 km/s, close to the spectral resolution limit), superimposed on a broader component (with FWHM velocity of 2800 km/s). This line profile of H_alpha is consistent with those observed in type-IIn supernovae. 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 7 (CBET 3334) Daniel W. E. Green