Though absent in Metroid II: Return of Samus, SR388's solar system was depicted in Metroid Fusion. Here is where SR388 was located, along with the Biologic Space Laboratories research station, as well as a second planet. The map to the right seems to show the rotation pattern of both planets (though they do not rotate in the map ingame) around the unseen sun. The flight path lists "P.1", "P.2" and "P.3", most likely indicating various points in space of Samus' travel to the BSL. After Samus sets the station to collide with SR388 and evacuates, the planets seem to have shifted in rotation downward. The explosion does not affect the neighboring planet, and Samus' location on the map is not listed.
SR388 is described as "nearby" Zebes in the Metroid Prime manual, implying that the system is close to the FS-176 system. However, in the Metroid Manga, SR388 is said to "not [be] found on many galactic charts". This can cause one to question where exactly SR388 and its system are located in the cosmos. In the Journal of Samus Aran, she says that this sector of space is ruled by a Federation governor.
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