2011CBET.2691....3C

J. Chen, J. Liang, and X. Wang, Tsinghua Center for Astrophysics, Tsinghua University; and T. Zhang and C. Wu, National Astronomical Observatories of China (NAOC), report on an optical spectrum (range 400-880 nm) of PSN J17100581+4222201 = SN 2011bi that was obtained on Apr. 8.80 UT with the 2.16-m telescope (+ OMR) at the Xinglong Station of the NAOC. The spectrum is consistent with that of a type-IIP supernova at about one month after maximum light. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2011bi matches that of SN 2004et at 23 days after maximum.