SUN to MOON

The Sun is a G-type main-sequence star comprising about 99.86% of the total mass of the Solar System. It is a near-perfect sphere, with an oblateness estimated at about 9 millionths, which means that its polar diameter differs from its equatorial diameter by only 10 kilometres (6.2 mi).Since the Sun consists of a plasma and is not solid, it rotates faster at its equator than at its poles. This behavior is known as differential rotation and is caused by convection in the Sun and the movement of mass, due to steeptemperature gradients from the core outwards. This mass carries a portion of the Sun’s counter-clockwiseangular momentum (as viewed from the ecliptic north pole), thus redistributing the angular velocity. The period of this actual rotation is approximately 25.6 days at the equator and 33.5 days at the poles. However, due to our constantly changing vantage point from the Earth as it orbits the Sun, the apparent rotation of the star at its equator is about 28 days. The centrifugal effect of this slow rotation is 18 million times weaker than the surface gravity at the Sun’s equator. The tidal effect of the planets is even weaker and does not significantly affect the shape of the Sun.

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