  We present a compact expression for a coherent vertex operator in superstring
theory, in the Neveu-Schwarz sector, that can be easily extended to the Ramond
sector by supersymmetric transformations in target space. We give also an
explicit construction for the Ramond coherent vertex operator. These
constructions provide the use of the supersymmetric version of the Del
Giudice-Di Vecchia-Fubini operators and Operator Product Expansion techniques,
displaying manifest BRST invariance and after normal ordering also manifest
covariance. As a consistency check we compute tree level three-points
scattering amplitudes involving Neveu-Schwarz coherent vertex operators in
different superghost pictures. Extending these results to the closed
superstring, we give the expressions of the coherent vertex operators in the
case of type IIA and IIB theories.
