SIMBAD references

E. S. Rykoff, University of Michigan, on behalf of the ROTSE collaboration, reports the discovery of a supernova in unfiltered CCD images taken on June 2.04 (at mag about 18.2) and 3.03 UT (mag about 17.7) with the 0.45-m ROTSE-IIIc telescope at the 'High- Energy Stereoscopic Systems' site in Namibia. SN 2005cg is located at R.A. = 21h10m50s.42, Decl. = +0o12'07".4 (equinox 2000.0), which is 0".7 north and 0".4 west of the core of the apparent host galaxy (which the Sloan Digital Sky Survey gives as mag g' = 19.7); nothing is visible at this location on ROTSE-IIIc images taken on May 7.14 (limiting mag about 18.4). R. Quimby, University of Texas, adds that a spectrum (range 420-890 nm), obtained on June 3.40 with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) under very poor conditions by M. Shetrone and S. Rostopchin, shows SN 2005cg to be a type-Ia supernova. Taking narrow emission lines at 677 and 501 nm to be H_alpha and H_beta from the host galaxy gives a redshift of 9290 km/s (yielding an absolute magnitude of -15.9 for the host galaxy).