  We present diffraction limited spectroscopic observations of an infrared
flare associated with the radio source SgrA*. These are the first results
obtained with OSIRIS, the new facility infrared imaging spectrograph for the
Keck Observatory operated with the laser guide star adaptive optics system.
After subtracting the spectrum of precursor emission at the location of Sgr A*,
we find the flare has a spectral index of -2.6 +- 0.9. If we do not subtract
the precursor light, then our spectral index is consistent with earlier
observations by Ghez et al. (2005). All observations published so far suggest
that the spectral index is a function of the flare's K-band flux.
