Peter van de Kamp was a professor of astronomy at Swarthmore College from 1937 until 1972.
Already in the forties, he was looking for exoplanets. He gave lectures on the topic do stars have planets for astronomers groups in the fifties. In 1963 he made a big announcement, that he finally found an exoplanet. A large jovian was orbiting Barnard star with an orbit on 25 years. Barnard star is the closest single star system from earth only six light years away. Only Alpha Centauri a system that consists of three stars and a habitable exoplanet is closer. Barnard star is a very small red dwarf, with only 0.14 the mass of the sun and 15% of the sun's radius. Barnard's star is also a very fast moving star, the fastest on the sky, and in 10000 years it will be the star that is closed to our sun.
The claimed discovery was made with the wobble method, de Kamp detected with his instruments that it was a periodic distortion in the star motion. Over decades he took thousands of images of the star. Making these measurements this was very hard precision work as the shift in the blurry light of star was tiny as a sand corn, This discovery was, of course, a big sensation at the time de Kamp appeared in many big newspapers and in television shows. Later he also discovered another Jupiter sized planet orbiting the star with an orbit of 12 years.
Later some skeptical voices about these discoveries were raised from the science community. Astronomer George Gatewood analyzed de Kamps photos and could not make the same conclusions. Other planet discovered around other stars by de Kamp had an identical change of motion, and the anomaly often occurred after the lens was removed or cleaned. Decades later much better instruments could not make the same discoveries as de Kamp did. The discoveries were not real it was errors made with the instruments and in the analysis of data. Van de Kamp did not accept that his life work was wrong and kept defending his research and started to repeat his measurements. Van de Kamp died in 1995 at aged 93 he never found an exoplanet. The first confirmed detection of Exoplanets was a couple years earlier in 1992.
Peter van de Kamp was not really completely wrong about Barnard's star it probably does has a planet.
Last week on 14 November 2018 Ignasi Ribas team at the Institute of Space Studies of Catalonia and the Institute of Space Sciences, CSIC in Spain. Announced that after careful studies that with 99 percent certainty there is an exoplanet orbiting Barnard star. The planet that was discovered with the wobble method lies around 0.4 astronomical units from the star. The planet is a cold icy super earth with a size 3.2 times earth. The planet is called Barnard’s star b, and with mean temperatures at -170 C, the planet is likely not habitable. The planet is still not classified as confirmed exoplanet more analysis needs to be made to 100 percent rule out any natural stellar variations. There are also indications that there are other planets further away from the star.