Tau Ceti

Tau Ceti was the primary of the Tau Ceti system, located less than twenty light years from Sol, in the Alpha Quadrant. The system contained several inhabited planets: Tau Ceti Prime, Tau Ceti III, Tau Ceti IV. 

Tau Ceti's location was depicted on two Federation star charts. In the first chart, showing the location of this star in the Milky Way Galaxy, was first seen in 2293. ( production art)

In 2364, on several occasions that year, viewscreen readouts aboard the USS Enterprise (NCC-1701-D) showed the location of Tau Ceti, in the form of charts from the Enterprise library computer. 

History
Some time before 2151, the Tau Ceti system was the site of the Tau Ceti Accords, a set of peace agreements, signed between the Vulcan High Command and the Andorian Empire. 

At some point prior to 2268, the USS Enterprise (NCC-1701), under the command of Captain James T. Kirk, engaged and defeated a Romulan vessel near Tau Ceti, using the Cochrane deceleration maneuver. 

In Starfleet Academy's Kobayashi Maru scenario, in 2285, Amber on Tau Ceti IV was listed as the home port of the tanker/transport Kobayashi Maru. 

Some time before 2348, Jean-Luc Picard first met Walker Keel at an exotic bar on Tau Ceti III. Some time after this Keel introduced Jack Crusher to Beverly Howard. 

Some time before 2358, the father of Kathryn Janeway, Vice admiral Janeway, died under the polar ice cap of Tau Ceti Prime. 

Tau Ceti was the home of The Traveler. 

''In 2155, in the mirror universe, Tau Ceti was the system in which the Terran Empire lost twelve ships in a battle against alien rebels. Propaganda had spread that this was a major victory for the Terran Empire, when in fact it was a sign they were losing.''

Background information
In "The Explored Galaxy" star chart, Tau Ceti was located between the Tholian Assembly and Romulus. Both were identified in as being located in the Alpha Quadrant.

The chart naming stars within 20 light years of Sol was drawn by Rick Sternbach for the Star Trek Spaceflight Chronology in the late 1970s. Found on page 77, this chart showed Earth commercial and exploration routes after the use of warp drive began. Tau Ceti was the destination on an exploration route. According to the Spaceflight Chronology, the UNSS Bonaventure, under the command of Captain Hadrian Huckleby, began Earth's warp drive era with a trip to Tau Ceti four years after the first successful demonstration of warp technology.

According to The Worlds of the Federation, Tau Ceti III was the planet Kaferia, homeworld of the insectoid Kaferians. In and, The Traveler was also said to be a native of Tau Alpha C, suggesting Tau Alpha C was located in the Tau Ceti system.

According to Star Trek: Star Charts (pg. 44), from the mid-22nd century, Tau Ceti was located in or near Federation space, in the Alpha Quadrant. The planet Kaferia was the third planet. Tau Ceti was a G-class star with a magnitude of +5, which was the same brightness as Sol.

Apocrypha
According to the novel Enterprise: The First Adventure, Tau Ceti was located along the Romulan Neutral Zone and the inhabitants of Tau Ceti II were widely regarded as possessing great mineralogical expertise, using sapphires as the local currency.