Astrotheorist
An astrotheorist was a scientist who formulated theories about astronomy.

According to Kathryn Janeway, Federation astrotheorists believed that inversion nebulae were unstable and burned out within a few years. Upon locating one in 2372 that appeared to have lasted for centuries, Tom Paris speculated that the theorists might be wrong, as they had never seen one up close. Chakotay then corrected them both, saying that the theorists might be partially correct, as some of the nebula's plasma strands were about to ignite. ()

See also
 Astrotheory 101
Scientific occupations