1998A&A...335..637H

Monochromatic limb-darkening and monochromatic radii predicted by the non-Mira M giant models of Bessell et al. (1989A&AS...77....1B, 1991A&AS...89..335B) with 3500K≥T_eff≥2500K were computed for selected typical bandpasses used in interferometric and lunar occultation work. Problems of defining and measuring radii of extended-photosphere stars and the relationship between different assumptions on limb-darkening and 'measured' radii are discussed. Fits of simple uniform disk (UD), fully darkened disk (FDD) and Gaussian limb-darkening curves to the visibilities predicted by the non-Mira M giant models were performed. These fits show that the FDD curve is often a surprisingly good approximation to the model-predicted limb-darkening shape.