Stellar physics

From Memory Alpha, the free Star Trek reference

Stellar physics was the field of physics which studied stellar phenomenon within a star. It was distinguished from quantum physics and astrophysics, in the sense that the former studied sub atomic particles and the latter studied whole star systems at a time.

Beverly Crusher led a team of stellar physicists, including Dr. Reyga to study the effects of a star on metaphasic shields. (TNG: "Suspicions")