2008CBET.1314....1Y

F. Yuan, University of Michigan; R. Quimby, California Institute of Technology; D. Chamarro, 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 (mag about 18.8) in unfiltered CCD images taken on Mar. 12.28 UT with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory. The new object, which brightened to mag about 17.1 on Mar. 22.21, is located at R.A. = 11h51m47s.80, Decl. = +46o52'29".8 (equinox 2000.0), or 1".8 east and 6".7 north of the center of MCG +08-22-20 (whose SDSS redshift is z = 0.019). A finding chart for 2008bj is given at the following URL: http://rotse.net/rsvp/j115147.8+465230/j115147.8+465230.jpg. A spectrogram (range 420-890 nm) of 2008bj, obtained on Mar. 25.16 with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by J. Caldwell and V. Riley, shows it to be a type-II supernova. The spectra are similar to that of SN 2006bp at about 12 days after explosion (Quimby et al. 2007, Ap.J. 666, 1093).