Electromagnetic Signals from Planetary Collisions

Abstract

Planet-planet collisions are expected during the early stages of the formation of extrasolar planets and are also possible in mature planetary systems through secular planet-planet perturbations. We investigate the electromagnetic signals accompanied with these planetary collisions and their event rate and explore the possibility of directly detecting such events. A typical Earth-Jupiter collision would give rise to a prompt EUV soft X-ray flash lasting for hours and a bright IR afterglow lasting for thousands of years. It is suggested that with the current and forthcoming observational technology and facilities, some of these collisional flashes or the postcollision remnants could be discovered.