A comparison of synthetic and measured solar continuum intensities and limb darkening coefficients

The paper compares recent center-limb studies of optical and IR continuum intensities (over the wavelength range 0.3-2.4 microns, with the data tabulated in the form of second- and fifth-order polynomial fits to empirical limb darkening curves) by Pierce and Slaughter (1977) and by Pierce et al. (1977) with predictions based on several current photospheric thermal structure models, using calibrated specific intensity measurements by Labs and Neckel (1968, 1970) to set an absolute temperature scale. The thermal structure in best quantitative agreement with the measurements of Pierce and Slaughter and Pierce et al. is the semiempirical model of Vernazza, Avrett and Loeser (1976). The temperatures in this model must be scaled upward, however, by a factor of 1.015 plus or minus 0.0005 to be consistent with the Labs and Neckel absolute calibration of continuum high points in the 0.40-0.65 micron region.