Question

is the sun has a surface ?

Answer 1

This gas ball is held together by gravity alone. This means that the Sun does not have a firm surface. Nevertheless, the Sun seems to us a luminous sphere with a sharp edge. The reason for this is that the sunlight that we observe without any auxiliary means appears in a relatively thin layer. This layer, like the photosphere, has a thickness of only several hundred kilometers. Therefore, it makes sense to talk about the visible surface of the Sun.