Electronic Telegram No. 1317 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 2008bi IN NGC 2618 G. Folatelli, M. Hamuy, and N. Morrell, on the behalf of the Millennium Center for Supernova Studies and the Carnegie Supernova Project, report that they obtained a spectrum (range 320-1020 nm) of 2008bi (cf. CBET 1312) with the European Southern Observatory New Technology Telescope (+ EMMI) on Mar. 28.1 UT. The spectrum shows that 2008bi is a fast-declining type-Ia supernova at a few days afer maximum light. Using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024), 2008bi is found to be most similar to SN 1991bg at three days after maximum. Adopting a host-galaxy recession velocity of 4031 km/s (Oosterloo and Shostak, 1993, A.Ap. Suppl. 99, 379) for the host galaxy, NGC 2618, an expansion velocity of 9000 km/s is derived from the absorption minimum of the Si II 635.5-nm line. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 March 28 (CBET 1317) Daniel W. E. Green