I recently set up camp on a planet, rigged up a teleporter, and now I can't find the system itself. Does anyone know an easy way of finding the system? I know all the details apart from the coordinates. Any ideas?
Unfortunately, finding a specific system, and or planet requires knowing it's coordinates. Even if a coordinate is saved, between updates, these coordinates have a chance to be changed, or erased entirely.
If you named it, you should be able to teleport to it with another teleporter, but if not, the only other way would be to retrace backwards in your travel route (retracing your steps).
Since you can go to the planet, you can recover it's coordinates.
Go there and back to your ship so it's the last world used.
Then find your starbound universe storage folder, e.g. /steamapps/common/starbound/storage/universe ; steam users can also use the "browse local files" button i believe.
Sort this folder by modify date and look for the most recent world file. The numbers in the name mean [xcoord][ycoord][seed?][orbit][suborbit].