Electronic Telegram No. 933 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2007bk H. Mikuz, Ljubljana, reports the discovery of an apparent supernova (mag 16.5) on four unfiltered CCD images taken around Apr. 20.005 UT with the 0.60-m f/3.3 Cichocki reflector in the course of the Comet and Asteroid Search Program (PIKA) at Crni Vrh Observatory. The new object is located at R.A. = 15h28m45s.58, Decl. = +58o52'12".8 (equinox 2000.0), which is approximately 5".0 east and 12".5 north of the center of a nearby faint galaxy. Nothing is visible at this location on three consecutive unfiltered PIKA images obtained on 2005 Apr. 4.882 (limiting mag 18.5) or on several Palomar Sky Survey and 2MASS images from the Aladin database. A confirming R-filtered image of 2007bk taken on Apr. 20.950 yields magnitude R = 16.65 +/- 0.02. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 April 21 (CBET 933) Daniel W. E. Green