Epsilon Eridani (also known as Delta Orcus and Toredar) is a star, an orange star that is visible from Earth in the Eridanus constellation, some 10.5 light-years distant. This star system contains the planet Axanar, and is located in the general vicinity of 61 Ursae Majoris, Sirius and the Tau Ceti system. (ST reference: Star Charts)
|Stars, systems and objects of the Eridanus constellation|
|1 Eridani (Tau-1 Eridani) • 3 Eridani (Azha, Eta Eridani) • 13 Eridani (Zibal, Zeta Eridani) • 14 Eridani • 18 Eridani (Delta Orcus, Toredar, Epsilon Eridani) • 23 Eridani (Rana, Delta Eridani) • 34 Eridani (Gamma Eridani, Zaurak) • 38 Eridani (Beid, Omicron-1 Eridani) • 40 Eridani (Keid, Omicron-2 Eridani, Vulcanis) • 59 Eridani • 67 Eridani (Cursa, Beta Eridani) • 82 Eridani • 88 Eridani • 198 Eridani • Alpha Eridani (Achernar) • Beta Eridani (Cursa, 67 Eridani) • Chi Eridani (Caleb, Kaleb) • Delta Eridani (Rana, 23 Eridani) • Epsilon Eridani (Delta Orcus, Toredar, 18 Eridani) • Eta Eridani (Azha, 3 Eridani) • Gamma Eridani (34 Eridani, Zaurak) • Iota Eridani • Omicron-1 Eridani (Beid, 38 Eridani) • Omicron-2 Eridani (Keid, 40 Eridani, Vulcanis) • p Eridani • Tau-1 Eridani (1 Eridani) • Tau Eridani Cloud • Theta Eridani (Acamar) • Zaurak (34 Eridani, Gamma Eridani) • Zeta Eridani (Zibal, 13 Eridani)|
Epsilon Eridani was identified as Vulcan's star in the reference book Spaceflight Chronology, as well as in the TOS novel: Strangers from the Sky. However, in 1991, Gene Roddenberry along with three astrophysicists determined 40 Eridani A (first suggested as the Vulcan sun by James Blish in Star Trek 2) was the more likely candidate. This has subsequently been reinforced in other novels, and canonically in the ENT episode: "Home".
Real-life astronomy currently has determined Epsilon Eridani to be a singular star with a large gas giant planet, but Star Charts shows the location as a binary star, although some binaries listed in Star Trek publications use that description for systems with stellar-sized gas giant companions instead of additional stars. FASA RPG module: The Four Years War provided Axanar the alternate system name Delta Orcus and called this a K0 type orange dwarf, another slight difference from real-life observations.
In the name "Delta Orcus", the stellar notation using the Greek language letter "delta" indicates that there might be a star group or constellation of some sort named "Orcus", of which Delta Orcus would logically be indicated to be the fourth most prominent star or system.