  Sub-arcsecond imagery (HRCAM, 0".35 - 0".57 FWHM) and two-dimensional
spectrography (TIGER, 0".9 FWHM) of the central nucleus of M31 have been
obtained at CFHT. The photometric data clearly show the double-peaked nucleus,
in excellent agreement with a recent HST image by Lauer et al. 1993. We built
deconvolved surface brightness models, using the multi-Gaussian expansion
method. We then perform a detailed morphological analysis of the three central
photometric components (bulge, nucleus and bright secondary peak) and derive
various spatial luminosity models (oblate and triaxial). Stellar velocity and
velocity dispersion fields were derived from the TIGER data: the former
displays an extremely rapid rotation around the true center of the galaxy,
while the latter exhibits a peaked structure offset in the opposite direction
of the brightest light peak. Neglecting these offsets,both extended versions of
the virial theorem and detailed hydrodynamical models confirm the classical
strong central mass concentration, perhaps a supermassive black hole of about
7.10**7 Msun, as well as a large excess of circular motions. These offsets,
however, suggest that the nucleus presently undergoes a strong stellar
oscillation, with non-stationary, non-axisymmetric dynamics. This too reopens
the case for a strong central mass concentration.
