  Time-dependent thermal X-ray spectra are calculated from physically plausible
conditions around GRB. It is shown that account for time-dependent ionization
processes strongly affects the observed spectra of hot rarefied plasma. These
calculations may provide an alternative explanation to the observed X-ray lines
of early GRBs afterglows (such as GRB 011211). Our technique will allow one to
obtain independent constraints on the GRB collimation angle and on the
clumpiness of circumstellar matter.
