The discussion focuses on converting angular size from arcseconds to steradians for spherical objects. It is established that arcseconds represent an angle, while steradians represent a solid angle, making direct conversion impossible without additional information about the object's shape. To calculate the solid angle in steradians, one must use the formula that involves the subtended angle (theta) and the distance from the observer (R), specifically dividing the visible area by R².
PREREQUISITESAstronomers, physicists, and students studying geometry or optics who need to understand the relationship between angular measurements and solid angles.
Orodruin said:You don't, not unless you know the shape of the object. An arcsecond is an angle and a steradian is a solid angle, they are different things. It is like asking how to convert a length into an area.
Since you are working with arcsecs, I assume we're discussing very small angles. If the subtended angle (of a diameter) is theta and the distance from the observer is R, what, roughly, is the visible area? Divide that by R2 and you have the steradians.Teenion said:I know its spherical object (I should have mentioned it in my first post)..
Yeah, converting is not a good word for what I want to do.. Better question would be How can I obtain the size of the spherical object in steradians if I know the angular size in arcsecs.