The answer is artist, but for other reasons. RA is the sun god but also stands for Royal Academy, denoting membership of this prestigious organisation for successful artists!
It's not - if you are a successful artist then you are invited to be a member of the Royal Academy and are allowed to put the letters RA after your name ie RA follows the name of a successful artist.
I know all that but I am trying to fit your answer to the clue which talks of Sun God (ie RA ) following A . Are you saying that 'apparently' reverses the letters to AR ?
What I'm trying to say and obviously not being very clear is that there is no anagram or other cryptic part of the clue - once you have that the sun god is RA then you have to think what sort of successful one would have the letters RA following its name, the apparently is merely that it is not the sun god RA but that RA is for Royal Academy (of Arts).