Superconducting cosmic strings may carry lightlike current pulses after they have passed through a region where a magnetic field was present. If one such string happened to be between us and a distant star, it would produce a double image of this star. The passage of a lightlike current pulse would make this double image move with time, and should therefore provide a means to observe an unambiguous string signature which is discussed here. Details on the material contained in this article may be found in Garriga & Peter, 1994.