The importance of FeI as a continuous opacity source in the solar atmosphere

The inability of theoretical model fluxes to fit the observed solar flux in the UV, the "missing UV opacity problem," results in erroneous abundances derived from UV lines. For example, S. Balachandran and R. A. Bell recently argued that the solar beryllium abundance, derived from Be II lines at 3130 Angstrom, was not depleted but rather equal to the meteoritic value with critical implications on mixing and angular momentum transport models. In this Letter we have incorporated recent Iron Project calculations of the Fe I bound-free opacity into our calculations of the continuous opacity. By combining this with observed line blocking, we compare the predicted fluxes to the observed solar flux in the 2000-4000 Angstrom region. We find that a reasonable fit to the observed flux between 3000 and 4000 Angstrom is obtained with twice the Fe I bound-free value recently derived by M. A. Bautista. The importance of this and other metal bound-free opacities is discussed.