Limb darkening

A filtered image of the Sun in visible light, showing the limb-darkening effect as a dimmer luminosity towards the edge or limb of the solar disk. The image was taken during the 2012 transit of Venus (seen here as the dark spot at the upper right).

Limb darkening is an optical effect seen in stars (including the Sun) and planets, where the central part of the disk appears brighter than the edge, or limb.[1] Its understanding offered early solar astronomers an opportunity to construct models with such gradients. This encouraged the development of the theory of radiative transfer.

  1. ^ Roun, Daniel (2003). "Limb Darkening". In Gargaud, Muriel; Amils, Ricardo; Quintanilla, José Cernicharo; Cleaves, Henderson James; Irvine, William M.; Pinti, Daniele L.; Viso, Michel (eds.). Encyclopedia of Astrobiology. Berlin, Heidelberg: Springer. pp. 925–926. doi:10.1007/978-3-642-11274-4_885. ISBN 978-3-642-11271-3.