Electronic Telegram No. 1927 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 2009io IN UGC 11666 T. Boles, Coddenham, England, reports the discovery of an apparent supernova (mag 18.9) on an unfiltered CCD images taken on Aug. 13.932 and 29.032 (limiting mag 21.0) with a 0.35-m reflector. The new object is located at R.A. = 21h02m15s.08 +/- 0s.01, Decl. = +15o08'29".8 (equinox 2000.0), which is approximately 2".2 west and 20".0 north of the center of UGC 11666. Nothing is present at this position on Boles' images from 2008 Aug. 4 and 2007 Oct. 6 (limiting mag 19.5) or on Digitized Sky Survey plates from 1991 July 16 (limiting red mag 21.0) and 1992 Oct. 16 (limiting blue mag 20.5). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 August 29 (CBET 1927) Daniel W. E. Green