THE STELLAR DYNAMICS OF M87

We extract the shape of the stellar velocity ellipsoid as a function o f radius in M87 from van der Marel's [MNRAS, 270, 271 (1994)] velocity dispersion data. We include the gravitational force of a central blac k hole with the mass quoted by Harms et al. [ApJ, 435, L35 (1994)]. Th e kinematical data are corrected for the effects of seeing and instrum ental blurring using a nonparametric algorithm. We find that the stell ar motions in M87 are slightly radially anisotropic throughout the mai n body of the galaxy, with sigma(r) approximate to 1.2 sigma(t). Howev er, sigma(t) exceeds sigma(r) within the inner 1'' - 2'' by a statisti cally significant amount. A number of models for the formation of nucl ear black holes predict a tangential anisotropy in the stellar motions , and our results provide evidence for such an effect in M87. (C) 1997 American Astronomical Society.