40 Eridani, commonly known as known as the Vulcan system (or Vulcanis system), is 16 lightyears from Earth and the location of the planet Vulcan. It is a trinary system, with 40 Eridani A being the main star. The other two stars in the system, 40 Eridani B and 40 Eridani C, orbit 40 Eridani A every 8,000 years and each other every 250 years or so. The 40 Eridani A Starfleet Construction Yards and the Hephaestus Fleet Yards are located in this system. (TNG: "Night Terrors", "The Wounded"; Star Trek: Liberty)