Electronic Telegram No. 1723 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 2009as IN ESO 447-37 R. Covarrubias, Observatories of the Carnegie Institution of Washington (OCIW) and Anglo Australian Observatory; and N. Morrell, OCIW and the Carnegie Supernova Project, report that a spectroscopic observation (range 400-1000 nm) of 2009as (cf. CBET 1717), obtained on Mar. 15.4 UT with the Magellan II Clay telescope (+ LDSS3) at Las Campanas Observatory, shows this to be a type-Ia supernova. Cross-correlation with a library of supernova spectra, using the "Supernova Identification" code (SNID; Blondin and Tonry, 2007, Ap.J. 666, 1024), gives a very good match with several normal type-Ia supernovae between 10 and 14 days after maximum. Adopting the NED recession velocity for the host galaxy of 6649 km/s (Theureau et al. 2007, A.Ap. 465, 71), the minimum of the Si II 635.5-nm absorption reveals an expansion velocity of approximately 11700 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 March 15 (CBET 1723) Daniel W. E. Green