  We point out that solar neutrino oscillations with large mixing angle as
evidenced in current solar neutrino data have a strong impact on strategies for
diagnosing collapse-driven supernova (SN) through neutrino observations. Such
oscillations induce a significant deformation of the energy spectra of
neutrinos, thereby allowing us to obtain otherwise inaccessible features of SN
neutrino spectra. We demonstrate that one can determine temperatures and
luminosities of non-electron flavor neutrinos by observing bar{nu}_{e} from
galactic SN in massive water Cherenkov detectors by the charged current
reactions on protons.
