  The discovery of hundreds of young, bright stars within a parsec from the
massive black hole at the center of the Galaxy presents a challenge to star
formation theories. The requisite Roche densities for the gravitational
collapse of gas clouds are most naturally achieved in accretion disks. The
water maser sources in Keplerian rotation in the nuclei of NGC4258, NGC1068,
and the Circinus galaxy indicate the presence of warm, extended, molecular
accretion disks around black holes similar in mass to the one at the Galactic
center. Here we argue that the current conditions in the maser nuclei, and
those near the Galactic center, represent two consecutive, recurrent phases in
the life cycle of the nucleus of a typical gas-rich spiral bulge. The warm
molecular disks that give rise to the observed maser emission fragment into
stellar-size objects. The stellar masses, their orbital geometry, and the total
number of stars thus formed are consistent with the values identified at the
Galactic center. The stars tend to form in compact groups resembling the IRS 13
complex that dominates the stellar light in the neighborhood of the black hole.
