The decrease in brightness of an object towards its edges. Limb darkening is most noticeable at optical wavelengths in the Sun, where we see into deeper, hotter (and therefore brighter) layers at the centre of the Sun's disk than at the limb. Characteristic features in the light curves of certain eclipsing binaries demonstrate the existence of limb darkening in these stars. Limb darkening is also noticeable in the gaseous giant planets.
Subjects: Astronomy and Astrophysics.