High Quality Content by WIKIPEDIA articles! 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 the constellation Eridanus. The primary star of the system, 40 Eridani A, is easily visible to the naked eye. The pair 40 Eridani B/C was discovered on January 31, 1783, by William Herschel., p. 73 It was again observed by Friedrich Georg Wilhelm Struve in 1825 and by Otto Wilhelm von Struve in 1851. In 1910, it was discovered that although component B was a faint star, it was white in color. This meant that it had to be a small star; in fact it was a white dwarf, the first discovered.