Question

select the correct answer.
what is limb darkening?
a. the periphery of the chromosphere appears darker than the center.
b. the periphery of the corona appears darker than the center.
c. the periphery of the core appears darker than the center.
d. the periphery of the photosphere appears darker than the center.

Explanation:

Limb darkening is a phenomenon in solar physics. The photosphere is the visible surface of the Sun. In limb darkening, the light from the periphery (limb) of the photosphere appears darker than the light from the center. This is because at the limb, we are looking at a shallower layer of the photosphere (less material along the line - of - sight), and the temperature decreases with height in the photosphere. So, the cooler material at the limb emits less light (appears darker). The chromosphere is a layer above the photosphere, the corona is the outermost layer of the Sun's atmosphere, and the core is the innermost part where nuclear fusion occurs. These other layers (chromosphere, corona, core) are not the location where the limb darkening phenomenon is observed as described in the options.

Answer:

D. The periphery of the photosphere appears darker than the center.