Prospects for Comet Kohoutek (1973f)

Abstract

An assessment is made of the status of this newly discovered comet, which is speeding towards perihelion passage at about the end of the year and which may prove to be the most spectacular comet of the century. It is thought that present estimates of its eventual maximum brightness may be optimistic. On the basis of the icy nucleus'' model activity ln the form of tail production and interaction with the solar wind should be well under way early In December 1973; but on the basis of the widely spaced dust particle swarm model for the structure of comets more precise prediction can be made for the time of onset of strong tail production, and this prediction is substantially different from that suggested by the former model, and may provide a crucial test between the two models. It is pointed out that the comet will be very awkwardly situated when near perihelion for observation from Earth because of the proximity of the Sun to the line of sight. Observation of the tail shortly after perihelion should, however, become possible from Earth, and the geometrical conditions continue suitable as the comet recedes from the Sun. The applicability for space vehicles formore » observational purposes is discussed. With regard to emission spectra the comet should certainly exhibit the presence of volatile radicals, and even elements such as Na, Mg, Ni, and possibly Fe. The shape and size of the comet are also discussed. (UK)« less