NEW F-VALUES IN CI AND THE CNO ABUNDANCES IN THE SUN

In an attempt to refine our knowledge of the solar abundances of the C NO elements, we discuss in this paper the implications of a new accura te set of oscillator strengths recently calculated in intermediate cou pling for the 2p(2P(o))nl-2p(2P(o))n'l' E1 transitions of astrophysica l interest in C I and also for the forbidden transitions within the 2p 2 ground configuration. As with previous analyses devoted to nitrogen and oxygen, configuration interaction effects have been considered in the calculations in a detailed way and empirical adjustments have been introduced in the diagonal Hamiltonian matrix elements in order to im prove the agreement between theoretical eigenvalues and experimental e nergy differences. The new LTE result, based on a sample of 55 E1 tran sitions observed in the visible and in the near infrared regions, is A (C) = 8.60 +/- 0.03 in the usual logarithmic scale. Taking departures from LTE into account leads, for a sample of 31 weak lines, to a mean result A(C) = 8.57 +/- 0.03 in agreement with recent determinations.