2011CBET.2638....1P

S. B. Pandey and A. Romadan, University of Michigan; J. Vinko, University of Szeged; R. Quimby, California Institute of Technology; N. Whallon, B. Sandler, W. Zheng, F. Yuan, and C. Akerlof, University of Michigan; 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 17.0) in unfiltered images taken on Jan. 14.10 UT with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory. The new object is located at R.A. = 23:40:11.52, Decl. = +27:25:42.2 (equinox 2000.0; uncertainty about 1"), which is 6".4 east and 2".2 south of the center of the host galaxy (2MASX J23401103+2725444) that is in turn part of the underlying galaxy cluster. A finding chart for the object can be found at the following website URL: http://www.rotse.net/rsvp/j234011.5+272542/j234011.5+272542.jpg. A spectrum, taken on Jan. 15.07 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by J. Caldwell, shows that the new object is a type-Ia supernova, several days after 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 1995E (at 10.0 days after maximum) and SN 1996X (at 7.8 days after maximum). The median redshift estimate is z = 0.031. Adopting this redshift, the velocity (from the absorption minimum of the Si II 635.5-nm feature) is 12100 km/s.