バーナード星
In the 1960s astronomer Peter van de Kamp claimed that he had discovered a planet orbiting Barnard's Star using astrometry. Two papers from 1973 were most influential in discrediting this claim. The first, by John L.Hershey, identified systematic errors in the telescope that van de Kamp had used. The second paper was authored by Gatewood and Heinrich Eichhorn, who repeated the astrometry measurements made by van de Kamp with improved equipment and failed to detect any sign of Barnard's Star companions.