  The results of a next-to-leading order calculation of heavy quark production
in longitudinally polarized photon-nucleon collisions are presented. At c.m.
energy $\sqrt{S}=10$ GeV, for $\vec \gamma +\vec p \to c+X$, cross sections
differential in the transverse momentum and rapidity of the charmed quark $c$
and the corresponding asymmetries are presented; also, as functions of
$\sqrt{S}$, integrated cross sections, $K$-factors and the corresponding
asymmetries are given. Errors in the asymmetries are estimated and the
possibility to distinguish between three scerarios differing essentially in the
polarized gluon distribution is discussed.
