Search for radio and optical bursts from catastrophic events

The 10-meter optical reflector at Mount Hopkins in southern Arizona is equipped with two 4.6-meter radio dishes. The combined antennas have been used to search for broadband electromagnetic pulses of duration 0.1 to 20 sec, from regions of high stellar density at three radio frequencies (378 MHz, 385 MHz, and 610 MHz) and one optical frequency. Dispersion by interstellar electrons causes a predictable time delay and pulse widening at the lower frequencies so that pulses of cosmic origin can be disfinguished from interference pulses of local origin. The galactic center, the Coma cluster of galaxies, and the Andromeda galaxy were studied with null results. Broadband pulses might be expected to accompany the emission of bursts of gravitational radiation or gamma-ray bursts. Key words: optical bursts - radio bursts - catastrophic events