2008CBET.1532....1Y

F. Yuan, University of Michigan; R. Quimby, California Institute of Technology; D. Chamarro and M. D. Sisson, University of Michigan; A. Uecker, Indiana University of Pennsylvania; C. Akerlof, University of Michigan; and J. C. Wheeler, University of Texas, on behalf of the ROTSE collaboration, report the discovery of a supernova (mag about 18.8) in unfiltered CCD images taken on Sept. 27.46 UT with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory. The new object, which also was observed near mag 19 over the following few days, is located at R.A. = 1h20m44s.03, Decl. = +14o41'37".0 (equinox 2000.0), which is 6".6 west and 2".7 south of the center of its apparent host galaxy (with z = 0.059 as measured by the Sloan Digital Sky Survey). A finding chart has been posted at the following website URL: http://www.rotse.net/rsvp/j012044.0+144137/j012044.0+144137.jpg. A spectrum (range 420-890 nm), obtained on Oct. 1.21 with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by S. Odewahn and A. Westfall, shows 2008gd to be a type-II supernova. Weak H-alpha, H-beta, and He I/Na I lines are detected. Reference to SNID (Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that the spectra are similar to that of type-IIP supernovae around maximum light or to the type-IIL supernova 1979C at 11 days after maximum, both at redshift consistent with the host. The shape of the lightcurve is not well constrained by the ROTSE photometry with its limited signal-to-noise.