SUN

(Ger. sonne.) In Astronomy, the central body of our system, about which all the planets and comets revolve, and by which their motions are regulated and controlled. In Physics, the sun is the source of light and heat; and therefore the primary cause of all the motions and changes effected on the surface of the earth by those great agents of nature. Apparent Magnitude of the Sun. — The sun presents to the naked eye the appearance of a luminous circular disc, sub- 4 G [s. 1215]