How to get this bonus 100 XP? NOT excellent throw! [duplicate]

Sometimes I get a bonus when catching a Pokemon. When does this happen? It happened already multiple times to me.

(I don't mean curveball, great or excellent bonus here. I mean the undefined "bonus" visible in the screenshot)

Bonus


Solution 1:

This bonus is from catching a Pokemon on your first attempt, regardless of catching it before or its CP.

Source: Just from testing. Edit: Being new this may be a coincidence.