40 Eridani
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Template:Starbox begin Template:Starbox observe Template:Starbox character Template:Starbox astrometry Template:Starbox detail Template:Starbox catalog Template:Starbox end 40 Eridani (also known as Omicron2 Eridani, or Keid, from the Arabic word qayd "(egg) shells") is a triple star system less than 16.5 light years away from Earth. It is in constellation Eridanus and was discovered to be a double star in 1783 by William Herschel. In 1851, Otto Wilhelm von Struve discovered that one of the stars in the double was itself a double.
In 1910 it was discovered that component B was actually a white dwarf star, which meant it had already evolved through its main sequence stage. In fact this was the first white dwarf star to be discovered. While it was a main sequence star, this was the most massive member of this system but it ejected most of its mass toward the end of its life.
General information
The primary star of 40 Eridani is an orange main sequence dwarf of spectral type K1, observed to be about 4 billion years old. The two companion stars, 40 Eridani B, a 9th magnitude white dwarf (spectral type A VII) and 40 Eridani C an 11th magnitude red dwarf (spectral type M4e V), orbit each other 400 astronomical units from the primary star. Component C is a flare star with variable star designation DY Eridani.
40 Eridani in fiction
In the Star Trek fictional universe, 40 Eridani A is the location of the Vulcan home planet. Although this was never stated on any TV show or film, both the authorized Star Trek book Star Trek: Star Charts and Gene Roddenberry (see [1]) give this location. In addition, Commander Tucker's statement in Star Trek: Enterprise that Vulcan is 16 light years from Earth confirms this.