PX282 - C13 - limb darkening

image: John Chumack

• the limb of a star, ie. the boundary disc, is seen to be dimmer and redder
• this is due to the temperature gradient within the photosphere
• when looking at a star, the light from the centre region is coming radially outwards and originate from deep in the photosphere
• the light from the limbs are coming at an angle and the originate from the upper reaches of the photosphere
• since the temperature increases further down, the light from the centre is less red and more intense

image: Michael Richmond