Electronic Telegram No. 880 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 N. Morrell and G. Folatelli, on behalf of the Carnegie Supernova Project, report that a spectrum of 2007ai (cf. CBET 870), obtained on Mar. 10.38 UT with the Baade 6.5-m telescope (+IMACS) at Las Campanas Observatory, shows this to be a type-Ia supernova near maximum light. Although the spectrum is noisy, it shows a blue continuum, and it clearly shows features due to Si II and S II that are peculiar to type-Ia supernovae. Assuming the NED recession velocity of 9492 km/s for the host galaxy (from Strauss et al. 1992, Ap.J. Suppl. 83, 29), the 'superfit' spectrum-comparison code (Howell et al. 2005, Ap.J. 634, 1190) provides a good match to the spectrum of SN 1999ee at one day before maximum light. Under the same assumption, the maximum absorption in the Si II 635.5-nm line indicates an expansion velocity of about 10000 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 March 12 (CBET 880) Daniel W. E. Green