The Pleiades system is a star system where Ford Prefect hacked into the British telephone service, and left his ship connected, running up a huge phone bill. Pleiadies Zeta, or Zondostina, is a star in this system. The Pleiades are also known as the "Seven Sisters".
Sesefras Magna is a huge orange gas giant which orbits Zondostina, and is home to Port Sesefron, a spaceport for Xaxisian battleships.
Epun is one of Sessefras Magna's moons. It is blue, small and cold.