Hyperion isn't a well-known figure from ancient Greek mythology, but astronomers should pay homage to him! This Titan was one of the twelve offspring of Uranus and Gaia, himself fathering Helios (Sun), Selene (Moon) and Eos (Dawn). He represented light and observation.
Greek historian Diodorus Siculus (90 BCE - 30 BCE) wrote of Hyperion:
[He] was the first to understand, by diligent attention and observation, the movement of both the sun and the moon and the other stars, and the seasons as well, in that they are caused by these bodies, and to make these facts known to others.