Electronic Telegram No. 939 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 2007bm IN NGC 3672 H. Navasardyan, S. Benetti, A. Harutyunyan, and M. Turatto, Istituto Nazionale di Astrofisica and Osservatorio Astronomico di Padova, report that a spectrogram (range 350-780 nm, resolution 2.2 nm) of 2007bm (cf. CBET 936), obtained on Apr. 22.90 UT with the Ekar-Copernicus 1.82-m telescope (+ AFOSC), shows it to be a type-Ia supernova. Assuming a recession velocity of 1866 km/s (from LEDA) for the host galaxy, the 'PASSparToo' spectrum-comparison code (Harutyunyan et al. 2005, ASP Conf. Ser. 342, 258) provides good fits to spectra of type-Ia supernovae around a week before B-maximum light, once the spectrum is corrected for extinction as derived from an intense (EW about 0.26 nm) Na I D interstellar absorption doublet. The phase is confirmed by the expansion velocity deduced from the Si II 635.5-nm absorption feature (about 12500 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 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.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 April 23 (CBET 939) Daniel W. E. Green