Calculations

(1) Small-Angle Formula: D = θ d / 206,265 arcseconds, where the number of arcseconds in a circle divided by 2π = 206,265

D = linear size of an object

θ = angular size of the object, in arcseconds

1° = 60 arcminutes = 3600 arcseconds

d = distance to the object

Angular size of our Sun

(1) D = θ d / 206,265

Linear size of our Sun = 1,391,400

1,391,400 km = θ (15,0000,000 km/206265 arcsec)

θ = 1,391,400 km / (150000000 km/206265 arcsec) = 1,913.31 arcsec = <b.0. 53</n>° ≈ about the size of a pea (6 mm or 0.23 in) from about two feet away.

Linear Size of Coruscant Prime

Here, we have to go to Legends to get an idea of what the answer should be. They describe Coruscant’s sun as blue-white in color[1]. To be that color, the sun would have to be between 3.6 and 13.2 solar radii (R_☉) in diameter (for reference, our sun is 2 R_☉ wide)[2]. So let’s just take the average for Coruscant Prime, and call it 4.8 R_☉

(2) 1 R_☉ = 695,700 km

4.83 R_☉ x 695,700 km/ R_☉ = 3,339,360 km, about 2 ½ times the size of our sun (so not tiny!)

Angular Size of Coruscant Prime

(1) D = θ d / 206,265 arcsec

3,339,360 km = θ x 229,000,000 km / 206265 arcsec

θ = 3,339,360 km / (229,000,000 km / 206265 arcsec) = 3007.83 arcsec = 0.85° ≈ size of a dime as seen from around 1.2 meters away (around 4 ft), so it would appear larger than our sun, but only just.