Apparatus to search for optical flashes of extragalactic origin

An apparatus is described to search for optical, point-like flashes in the sky at the time scale of seconds. Such flashes are expected to accompany gamma ray bursts (GRB) observed routinely by satellites and proven to be of extragalactic origin. So far only one such flash has been recorded shortly after the GRB, because standard methods of observational astronomy are not suitable for the time scale of seconds. In this paper, a novel approach is proposed based on experience from particle physics experiments. An apparatus is described which monitors the sky continuously. The large data stream is analysed on-line and potentially interesting events are selected by a multilevel trigger system. In the first phase of the project the apparatus consists of two CCD cameras, especially designed for this project and a robotic mount used to scan interesting regions of the sky. In the second phase the experiment will consist of two sets of 16 cameras on fixed mounts, covering almost all visible sky.