Angular
sizes
•Quite often we will need to find linear size of some object, given its distance and its angular size
Note –
the book leaves out the units of “arcsec”. Do not make that mistake yourself.
An example different than the one in the
book: How large is the sun?
The angular diameter of the sun is about 0.50. To convert that to arcseconds use:
0.5 deg ´ 60 arcmin/deg ´ 60 arcsec/arcmin = 1800
arcsec
The sun is 1.5 ´ 108 km away (= 1 astronomical unit). So
From our text: Horizons, by Seeds