SIMBAD references

A. Romadan and W. Zheng, University of Michigan; J. Vinko, University of Szeged; R. Quimby, California Institute of Technology; N. Whallon, S. B. Pandey, F. Yuan, and C. Akerlof, University of Michigan; P. Pasque and M. Verkinderen, Cousino High School; and J. C. Wheeler and E. Chatzopoulos, University of Texas, on behalf of the ROTSE collaboration, report the discovery of a new supernova (mag about 18.5) in unfiltered images taken on Dec. 2.20 UT with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory. The new object, which was observed again on Dec. 3.19 at mag about 18.6, is located at R.A. = 11:50:17.04, Decl. = +43:57:47.0 (equinox 2000.0; uncertainty about 1"), which is 0".2 east and 1".6 north of the center of the presumed host galaxy (SDSS J115017.02+435745.4). A spectrum, obtained on Dec. 5.45 with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by M. Shetrone, shows that 2010kn is a type-Ia supernova, a few days before maximum light. The spectrum contains the Si II 635.5-nm line and several other characteristic type-Ia-supernova features. According to SNID (Blondin and Tonry 2007, ApJ. 666, 1024), the spectrum most resembles those of SN 2002er (at 9.4 days before maximum) and SN 2000E (at 2.5 days before maximum). The median redshift estimate is z = 0.073, in good agreement with the spectroscopic redshift of the galaxy designated SDSS J115017.02+435745.4 (z = 0.071) via the Sloan Digital Sky Survey. Adopting this redshift, the velocity (from the absorption minimum of the Si II 635.5-nm feature) is 11000 km/s.