  We have used Hubble Space Telescope to obtain moderate resolution 1150-5700
Ang. spectroscopy of the nucleus of M33 and a blue star ~1 arcsec NNW of the
nucleus in an attempt to find the optical counterpart of the nuclear X-ray
source and to characterize stellar populations in the nuclear region. The STIS
spectra of the nucleus can be modelled in terms of two starbursts, one with a
mass of about 9000 solar masses at 40 Myrs and the other with a mass of about
76,000 solar masses at 1 Gyrs. The blue star is a late type O giant, with no
obvious spectral anomalies to indicate that it is associated with the luminous
X-ray source. The nuclear region is not heavily reddened; 2200 Ang absorption
features in the spectra of both the nucleus and the star are weak. The data and
the star formation history support the hypothesis that the M33 nuclear source,
the brightest persistent source in the Local group, is an ~10 solar mass black
hole binary.
