👉 Aperture is a term used in astronomy, specifically in the field of astrophysics and physics. It refers to the opening or narrowness of an object in space that allows light or other forms of electromagnetic radiation through. Apertures can be broadly classified into two types: spherical and elliptical. A spherical aperture is one where the radius of the opening is constant, while an elliptical aperture has a circular shape with varying radii around its center. In both cases, the aperture's size