Optical radiation associated with gamma-ray bursts

We have calculated approximate characteristics of the reprocessed optical radiation resulting from the absorption of a γ-ray burst of a nearby star. We estimate the overall reprocessing time scale, including contributions from γ-ray transfer and diffusion of the optical radiation. Diffusive cooling occurs by either a ''self-similar'' or a ''transparency'' wave for postabsorption stellar surface temperatures greater or less than 104 respectively. For different combination of stellar and γ-ray burst properties, the reprocessing time scale can vary from the duration of the γ-ray burst (approx. 1 s) to the maximum calculated cooling time (approx.103 s). For close binary systems, we calculate the number of optical photons per square centimeter expected at Earth, as a function of the observed γ-ray burst fluences and likely distances. If all γ-ray bursters are in close binaries, we predict about 102 detections per year by an all sky monitor of 200 photons cm-2 sensitivity. The 1928 optical event recently reported by Schaefer can be produced using the reprocessing model, for distances to the binary as large as 150 pc. However, the stellar companion required to account for the reported optical flux is likely to be brighter than current optical candidates