Electronic Telegram No. 186 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 2005da IN UGC 11301 M. Modjaz, P. Challis, and R. Kirshner, Harvard-Smithsonian Center for Astrophysics; and T. Matheson, National Optical Astronomy Observatory, report that a spectrogram (range 350-740 nm) of SN 2005da (cf. IAUC 8570), obtained by P. Berlind on July 26.26 UT with the F. L. Whipple Observatory 1.5-m telescope (+ FAST), reveals it to be a supernova, possibly a peculiar type-Ic supernova. No obvious lines of hydrogen or helium are detected. The spectrum consists of wide absorption features, similarly to peculiar type-Ic supernovae 1998bw and 2002ap (Foley et al. 2003, PASP 115, 1220). In contrast to supernovae 1998bw and 2002ap, it also exhibits a wide absorption trough at 585 nm, having removed the NED recession velocity of 4495 km/s for the host galaxy (from Falco et al. 1999, PASP 111, 438), which could be identified with Na I. There are peaks near 530 and 640 nm and absorptions near 470, 630, and 680 nm. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the formal IAU Circulars. (C) Copyright 2005 CBAT 2005 July 27 (CBET 186) Daniel W. E. Green