Electronic Telegram No. 3120 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 2012cj IN NGC 5156 = PSN J13284343-4854356 Colin Drescher, Calamvale, Queensland, Australia, reports the discovery of an apparent supernova (red mag 17.6) on unfiltered CCD images taken on May 18.479 and 19.307 UT by Stuart Parker (Oxford, Canterbury, New Zealand) with a 35-cm Celestron C14 reflector (+ ST10 CCD camera). The new object is located at R.A. = 13h28m43s.43, Decl. = -48d54'35".6 (equinox 2000.0; magnitude and position measured by Drescher), which is 7" west and 25" north of the nucleus of the galaxy NGC 5156. Nothing is visible at this position on an image taken by Parker on May 3.594 (limiting red mag 18.8). The variable was designated PSN J13284343-4854356 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012cj based on the spectroscopic confirmation reported below. J. T. Parrent and D. A. Howell report that a CCD spectrum (range 350-900 nm) of PSN J13284343-4854356 = 2012cj was taken with the Gemini South telescope on May 20 UT. The spectrum reveals Balmer-series P-Cyg profiles, and the minimum of the H-alpha absorption feature is blue-shifted by about 10500 km/s (assuming a host-galaxy redshift of z = 0.01 for NGC 5156). Comparisons to other spectra with "Superfit" (Howell et al. 2005, Ap.J. 634, 1190) show similar overlap with the type-IIP supernova 1999em near maximum light. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2012 CBAT 2012 May 23 (CBET 3120) Daniel W. E. Green