  We infer the dynamical masses of stars across the Hertzsprung-Russell (H-R)
diagram using wide binaries from the Gaia survey. Gaia's high-precision
astrometry measures the wide binaries' orbital motion, which contains the mass
information. Using wide binaries as the training sample, we measure the mass of
stars across the two-dimensional H-R diagram using the combination of
statistical inference and neural networks. Our results provide the dynamical
mass measurements for main-sequence stars from 0.1 to 2 M$_\odot$, unresolved
binaries and unresolved triples on the main sequence, and the mean masses of
giants and white dwarfs. Two regions in the H-R diagram show interesting
behaviors in mass, where one of them is pre-main-sequence stars, and the other
one may be related to close compact object companions like M dwarf-white dwarf
binaries. These mass measurements depend solely on Newtonian dynamics,
providing independent constraints on stellar evolutionary models and the
occurrence rate of compact objects.
