Electronic Telegram No. 1646 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 2009B IN UGC 4423 T. Boles, Coddenham, England, reports the discovery of an apparent supernova (mag 17.2) on an unfiltered CCD image taken on Jan. 2.806 UT with a 0.35-m reflector. The new object is located at R.A. = 8h30m51s.47, Decl. = +74o41'08".1 (equinox 2000.0), which is approximately 7".6 west and 6".8 south of the center of UGC 4423. SN 2009B was confirmed at mag 17.3 by R. Arbour (South Wonston, Hants, England) on an unfiltered image taken on Jan. 3.865; Boles measures end figures 51s.48, 07".9 from Arbour's image. Nothing is present at this position on Boles' images from 2008 Feb. 8 and 2007 Apr. 11 (limiting mag 19.5) or on Digitized Sky Survey plates from 1997 Feb. 10 (limiting red mag 20.5) and 1998 Jan. 1 (limiting blue mag 21.0). P. Challis, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf of the CfA Supernova Group, reports that a spectrum (range 320-850 nm) of 2009B, obtained on Jan. 3 UT by M. Calkins with the F. L. Whipple Observatory 1.5-m telescope (+ FAST), shows it to be a type-II-P supernova about week after explosion. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 January 3 (CBET 1646) Daniel W. E. Green