2011CBET.2868....2M

N. Morrell, Las Campanas Observatory, Carnegie Supernova Project; and S. Kafka, Departament of Terrestrial Magnetism, Carnegie Institution of Washington, report that they obtained a spectrogram (range 300-1100 nm; FWHM resolution 0.1 nm) of PSN J19542142-5842390 = SN 2011gv on Oct. 20.00 UT with the 6.5-m Magellan II (Clay) telescope (+ MagE). The spectrum of 2011gv consists of a blue continuum with superimposed incipient P-Cyg profiles of Balmer and He I 587.6-nm lines, consistent with a young type-II supernova. From emission lines of an underlying H II region, they derive a helicentric redshift of 0.00682 ± 0.0002, in good agreement with the recession velocity measured by Koribalski et al. (2004, A.J. 128, 16) for IC 4901. Considering this redshift, the minimum of the H-beta absorption appears blueshifted by approximately 8900 km/s. Na I D1 and D2 absorption from the host galaxy is observed with a total equivalent width of 0.05 nm. Cross-correlation with a library of supernvoa spectra using the Supernova Identification tool (SNID; Blondin and Tonry, 2007, Ap.J. 666, 1024) gives good matches to the spectra of the type II-P supernovae 1999em and 2005cs at maximum brightness.