The brightness of objects past neptune (but in our solar system) actually varies approximately as 1/d4 and not as 1/d2 for stars where d is distance from the sun for the object. why is this the case?

Dona wrote the characteristics of two types of galaxies as shown below: type a: has a large flattened core type b: does not have a regular shape which statement is correct? type a is an irregular galaxy and type b is a lens galaxy. type a is a lens galaxy and type b is an irregular galaxy. type a is a spiral galaxy and type b is an elliptical galaxy. type a is an elliptical galaxy and type b is a spiral galaxy.