Electronic Telegram No. 870 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://cfa-www.harvard.edu/iau/cbat.html SUPERNOVA 2007ai IN MCG -04-38-4 Further to IAUC 8813, W. Li reports the LOSS/KAIT discovery of an apparent supernova (mag 18.0) on an unfiltered KAIT image taken on Mar. 6.53 UT. The new object is located at R.A. = 16h12m53s.74, Decl. = -21o37'48".7 (equinox 2000.0), which is 5".1 east and 24".5 south of the center of MCG -04-38-4. Nothing was visible at this location on a KAIT image from 2006 Aug. 29.18 (limiting mag 19.0). G. Folatelli, on behalf of the Carnegie Supernova Project, confirmed 2007ai at magnitude J = 17.3 on Y- and J-band images taken with the 1-m Swope telescope (+ RetroCam) at Las Campanas Observatory on Mar. 8.40, with measured position end figures 53s.75, 48".5. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 March 8 (CBET 870) Daniel W. E. Green