The Sun is the star the Earth orbits, and is found in the Milky Way Galaxy. Other locations relevant to Metroid are Jupiter, mentioned in the Metroid Prime Trilogy art booklet. There is also a specific asteroid named Ceres, which gave the destroyed space colony of the same name its name.
Federation Solar System | Gaflar System | Kalandor region | Messina System | Extreme Galaxy
Milky Way Galaxy | Small star | SR388's solar system | Sun | Tetra Galaxy | Unknown Solar System