2010CBET.2224....2F

A. V. Filippenko, J. M. Silverman, I. K. W. Kleiser, and A. J. L. Morton, University of California, Berkeley, report that inspection of CCD spectra (range 340-1000 nm), obtained on Mar. 22 UT with the 3-m Shane reflector (+ Kast) at Lick Observatory, shows that 2010ay is a broad-lined type-Ic supernova similar to SN 1998bw (e.g., Patat et al. 2001, Ap.J. 555, 900), probably within a few days of maximum brightness. The redshift of the host galaxy, determined from strong, narrow emission lines produced by H II regions in the host galaxy, is 0.067, in agreement with the SDSS redshift cited above. By far the most prominent feature is a very broad peak centered roughly at rest wavelength 515 nm. Given that such supernovae are sometimes associated with long-duration gamma-ray bursts (e.g., Woosley and Bloom 2006, ARAA 44, 507), a search for a possibly corresponding GRB in the weeks prior to discovery (Mar. 17) should be conducted. Further observations of the supernova are encouraged.