How could you determine the diameter of the sun? What method do you use?

Question

Hailey Alvarez · Accepted Answer

From the angular spacing #alpha# of the solar disc, using diameter = 2 #tan(alpha/2)# AU = 2 X 149597870 X tan#(alpha/2)# km.

On the vernal/autumnal equinox day, at noon, the best place and time for accuracy is from a ship in the sea close to New Papua Guinea. The error will be minimal here because the latitude is close to zero and the Sun will be overhead. Naturally, similar locations for the right-overhead Sun on winter and summer solstices are found at latitudes 23.4 degrees S and 23.4 degrees N. As AU is only an estimate of the distance; for the equinox, AU is a fairly good approximation to the actual distance. However, the precision will be higher if the Sun's actual distance on the day of observation is applied. Some corresponding sample values of #alpha# and diameter are 0.5313 deg and 1387221 km.

Alexander Acosta · Answer

undefined The diameter of the Sun can be determined using the method of solar angular diameter measurement. This involves observing the apparent size of the Sun from Earth and applying trigonometry to calculate its actual diameter.