Everything is an aesthetic discipline.
^
If you get personal enrichment from something, it's aesthetic. So practically anything can be aesthetic
Objective beauty, on the other hand...
I'll refer you to my previous admission of ignorance.
What's the difference?
Between subjective and objective beauty?
Aesthetics is, broadly, the study of how external objects relate to internal experiences. So, the Mona Lisa has aesthetic value, or beauty, because it evokes certain pleasant, or "beautiful" experiences. Technically speaking, asparagus has aesthetic beauty, assuming you like like asparagus.
But that's clearly just subjective; someone else may find asparagus disgusting and the Mona Lisa the work of a talentless hack. So to argue that something is
objectively beautiful usually requires invoking some kind of metaphysical claim, tweaking the definition of beauty (not an entirely invalid thing to do), and perhaps even claiming that some people are just wrong about what's beautiful and what isn't.
There are a lot of long-winded philosophical terms wrapped up in this, which I'll avoid getting into here.