  We consider the spectrum, emissivity and flux of the electromagnetic
radiation emitted by the thin electron layer (the electrosphere) at the surface
of a bare strange star. In particular, we carefully consider the effect of the
multiple and uncorrelated scattering on the radiation spectrum (the
Landau-Pomeranchuk-Migdal effect), together with the effect of the strong
electric field at the surface of the star. The presence of the electric field
strongly influences the radiation spectrum emitted by the electrosphere. All
the radiation properties of the electrons in the electrosphere essentially
depend on the value of the electric potential at the quark star surface. The
effect of the multiple scattering, which strongly suppresses radiation
emission, is important only for the dense layer of the electrosphere situated
near the star's surface and only for high values of the surface electric
potential of the star. Hence a typical bremsstrahlung radiation spectrum, which
could extend to very low frequencies, could be one of the main observational
signatures even for low temperature quark stars.
