He needs a name!

He's a graduate student in Canterlot who spends his time researching the princesses--hence, the sun and the moon. He thought the rays from the sun in his mark were simply sunbeams until Twilight Sparkle completed the royal trifecta of heavenly bodies with her star.

Of course, at some point you have to get out of the books. One of his major ambitions is to interview a princess about the experience of ruling Equestria. Of course, Celestia and Luna are always far too busy, and Cadance was shipped off north... and then Twilight ascended. Seizing his chance, he applied for a grant, traveled to Ponyville, and started stalking the newest alicorn... for science, of course.