Electronic Telegram No. 92 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 2004eo IN NGC 6928 N. Morrell, Las Campanas Observatory, together with G. Folatelli and M. Hamuy, on behalf of the Carnegie Supernova Project, report that two spectra of SN 2004eo (cf. CBET 88) taken on Sept. 19.02 (range 455-960 nm) and Sept. 20.01 UT (range 385-920 nm) with the 2.5-m du Pont telescope (+ WFCCD spectrograph) reveal that this is a type-Ia supernova displaying the characteristic Si II (635.5, 413.0 and 597.2 nm) and S II (545.4 and 564.0 nm) features. The minimum of the Si II 635.5-nm line yields expansion velocities of 12 100 and 10 000 km/s, respectively, on the two nights, assuming the NED host-galaxy recession velocity of 4707 km/s. Photometric observations obtained with the 1-m Swope telescope by S. Gonzalez and W. Krzeminski yield the following B-band magnitudes: 2004 Sept. 18.00 UT, 17.59; Sept. 18.99, 17.13; Sept. 19.99, 16.74; Sept. 21.04, 16.47, Sept. 22.05, 16.21. These suggest that SN 2004eo will reach maximum light in the next 3-4 days. NOTE: These 'Central Bureau Electronic Telegrams' are intended to be preliminary announcements of items that later appear in the formal IAU Circulars. Citations should normally be made to IAUCs rather than to CBETs. (C) Copyright 2004 CBAT 2004 September 22 (CBET 92) Brian G. Marsden