Question

How do you calculate the diameter of the sun?

Answer 1

From the angular spacing `alpha` of the solar disc and the Earth Sun distance AU , the diameter of the Sun `D = 2 tan(alpha/2) AU`, nearly.

Explanation:

Overlooking the small difference between the diameter of the

visible solar disc and a little longer Sun's diameter, and likewise,

overlooking that the observer is a little nearer to the Sun than the

center of the Earth, an approximation to the diameter of the Sun's

diameter

`=2 tan (alpha/2) AU`,

where `alpha` is the angular spacing of the solar disc.

If the angle is a horizontal measurement, the approximation is for

the equatorial diameter ant the vertical spacing would approximate

the polar diameter..

1 AU = 149597871 km, nearly.

Explication with sample data.:

If the angular spacing `alpha=0.5334^o`,

`D = 2 tan(0.5334^o/2) X 149597871 km = 1392704 km`, nearly..