Harold Johnson (astronomer)

Harold Lester Johnson ( born April 17, 1921 in Denver, Colorado, † April 2, 1980 in Mexico City) was an American astronomer. He developed methods for accurate photometry of stars and other celestial objects.

Johnson went to school in Denver, where he studied mathematics up to Bachelor's degree in 1942. During the Second World War, he worked on the development of radar. After the war he studied astronomy at the University of California, Berkeley, and in 1948 completed his doctoral work at an electronic apparatus for the measurement of photographic plates from. Thus began a life-long employment methods to accurately measure the brightness of celestial objects.

In 1948 he moved to the Lowell Observatory in Flagstaff, and after a short stay already at the end of more than assistant professor to the Washburn Observatory of the University of Wisconsin in Madison. From 1950 to 1952 he was assistant professor at the Yerkes Observatory of the University of Chicago, and then returned to the Lowell Observatory, where he could devote himself entirely to the development of photoelectric photometry methods without teaching obligations and under favorable climatic conditions.

In 1953, he led the UBV system for light measurement in three different wavelength ranges to 0.365 micron, 0.44 micron, 0.55 micron and one that developed the standard. Color-magnitude diagrams in the UBV system were an important tool for investigating the properties of stars and the effects of interstellar extinction.

During his time as a professor at the University of Texas 1959-1962, and then at the University of Arizona extended his photometric system into the infrared, and dealt with spectroscopy of stars in infrared light. In the 1960s, he established links with astronomical institutes in Mexico and moved in 1979 at the Universidad Nacional Autónoma de México in Mexico City. Johnson died in 1980 of a heart attack.


  • Astronomer ( 20th century)
  • University teachers (Austin, Texas)
  • University teachers (Tucson )
  • University teachers (National Autonomous University of Mexico )
  • Americans
  • Born 1921
  • Died in 1980
  • Man