We construct analytic solutions of open superstring field theory in the
Berkovits formulation using boundary condition changing operators under some
regularity conditions, extending the previous construction in the bosonic
string. We also consider the gauge-invariant observables corresponding to
closed string one-point functions on the disk. We analytically calculate the
gauge-invariant observables for the solutions both in the bosonic string and in
the superstring and find the expected change of boundary conditions of the
disk.Comment: 33 pages, no figures, LaTeX2e; v2: minor corrections; v3: minor
revision, published versio