Carbon and oxygen production rates for comet Kohoutek /1973 XII/

Abstract

Comas of Comet Kohoutek in the resonance lines of atomic oxygen (1304 A) and atomic carbon (1657 A) were detected with a rocket-borne objective spectrograph on 1974 January 8 (R=0.43 AU). The luminosity at 1304 A was 3.5 x 10/sup 28/ photons s/sup -1/, and that at 1657 A was 5.4 x 10/sup 29/ photons s/sup -1/. The scale length for O was 1.4 x 10/sup 6/ km (reduced to 1 AU), about a factor of 3 smaller than expected for photoionization but about that predicted if charge exchange with solar wind protons is the main loss process. A Haser model with two approximately equal scale lengths summing to 1.6 x 10/sup 6/ km fitted the C coma. Since the photoionization scale length of C is much shorter than this, these scale lengths probably reflect those of parent molecules. We obtain production rates for the two atoms by taking the lifetime for O derived from the observed scale length for an outflow velocity of 1 km s/sup -1/, and the theoretical lifetime for C. In combination with the H production rates derived from L..gamma.. observations, these yield Q/sub H/ approx. = 4 Q/sub 0/ approx. = 7 Q/sub c/. (AIP)