Electronic Telegram No. 1505 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 2008fo F. Yuan, University of Michigan; R. Quimby, California Institute of Technology; D. Chamarro, University of Michigan; A. Uecker, Indiana University of Pennsylvania; M. D. Sisson and C. Akerlof, University of Michigan; and J. C. Wheeler, University of Texas, on behalf of the ROTSE collaboration, report the discovery of a supernova in unfiltered CCD images taken with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory (found by subtracting a reference image built from exposures taken in Aug. 2007). Approximate magnitudes for the new object: Aug. 7.15 UT, 18.4; 20.13, 17.6; Sept. 5.12, 18.2. SN 2008fo is located at R.A. = 16h40m12s.46, Decl. = +39o43'55".8 (equinox 2000.0; uncertainty < 1"), which is 5".6 west and 4".5 south of the center of its apparent host galaxy (SDSS J164012.94+394400.4; z = 0.030). A finding chart for 2008fo can be found at the following website URL: http://www.rotse.net/rsvp/j164012.5+394356/j164012.5+394356.jpg. Spectra (range 420-890 nm) of 2008fo were obtained on Sept. 5.13 with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by S. Odewahn and V. Riley. The use of "SNID" (Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that the spectra of 2008fo best matches that of the type-Ic supernova 2004aw at 23 days after maximum, at z = 0.027 +/- 0.005, which is consistent with the redshift of its apparent host. The best match found with the "Superfit" supernova spectral identification code of Howell et al. (2005, Ap.J. 634, 1190) is to the type-Ic supernova 1991A. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 September 11 (CBET 1505) Daniel W. E. Green