Chris (preliminary VLT): Most likeley a type Ia at z~0.55
Isobel (preliminary VLT + preliminary LRIS): z=0.56 from VLT? IMH not sure - cant make bumps match. LRIS data : maybe bumps but not very convincing. possibly z=0.58 if the spike is OII (but probably a bad sky line).
Chris (final VLT): SN? z?
Andy (final VLT): This is a very interesting SN. I normal Type Ia spectrum doesn't fit too well: S01-004.92a.p05.ps The observed data has been Savitzky-Golay smoothed and an E galaxy spectrum has been subtracted. SN 1991T at +10 days isn't much better: S01-004.91T.p10.ps. In general, the fact that there are no features in the blue part of the spectrum means that it is unlikely to be a Ia.
A much better fit is to the very strange SN 1991L at z=0.36. There is only one spectrum of this SN available, and the epoch is not known. The type is thought to be a SN Ib/c, but even that is not certain. See my comparison at S01-004.91L.ps and also Matheson et al. 2001, ApJ, 121, 1648 The observed data has been Savitzky-Golay smoothed.
I think we can upgrade its status to SN I, probably SN Ib/c