|Out of Universe information|
|First mention||"Children of the Gods"|
- Colonel Jack O'Neill: Oh, here we go. Another scientist. General, please.
- Captain Samantha Carter: Theoretical astrophysicist.
- O'Neill: Which means?
- Major General George Hammond: Which means she is smarter than you are, Colonel. Especially in matters related to the Stargate.
- — (SG1: "Children of the Gods")
An astrophysicist is a scientist who studies the physics of the universe, especially the physic properties (lightness, density, temperature and chemical composition) of the celestial bodies like galaxies, stars, planets, exoplanets and interstellar material and the interactions with each other