Astrophysics
From Memory Alpha, the free Star Trek reference.
Astrophysics is a branch of astronomy that deals with the physics of astronomical objects in the universe. One who studies in this field is known as an astrophysicist.
Jadzia Dax held a Premier Distinction in astrophysics. (DS9: "Dax") Astrophysics was also one of Arjin's "better subjects." (DS9: "Playing God") Tom Paris majored in astrophysics at Starfleet Academy. (VOY: "Future's End")
The Astrophysics Department aboard the USS Enterprise-D used a newly upgraded sensor array, dubbed the "La Forge sensor array", which was used to conduct scans of the Amargosa Diaspora in 2368. (TNG: "Schisms")
