2011CBET.2708....3Z

T. Zhang and Z. Zhou, National Astronomical Observatories of China (NAOC); X. Wang, Tsinghua Center for Astrophysics, Tsinghua University, report on an optical spectrum (range 350-870 nm) of PSN J11554556+5519338 = SN 2011by that was obtained on Apr. 27.5 UT with the 2.16-m telescope (+ BFOSC) at the Xinglong Station of the NAOC. The spectrum is consistent with that of a type-Ia supernova at very young phase. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that this supernova matches that of SN 2003du at about 10 days before maximum. After removal of the host-galaxy recession velocity of about 850 km/s, they find the absorption minimum of the Si II 635.5-nm line to be blueshifted by about 12000 km/s. Further follow-up observations of this object are encouraged.