Photospheric abundances: Problems, updates, implications

Abstract

Current problems encountered in the spectroscopic determination of photospheric abundances are outlined and exemplified in a reevaluation of C, N, O, Ne, Mg, Si, and Fe, taking effects of NLTE and granulation into account. Updated abundances of these elements are given in Table 2. Specific topics addressed are (1) the correlation between photospheric matter and CI chondrites, and the condensation temperature below which it breaks down (Figure 1), (2) the question whether the metallicity of the Sun is typical for its age and position in the Galaxy.