Seth Nicholson

Seth Nicholson

American astronomer who discovered several of Jupiter's moons and asteroids
Date of Birth: 12.11.1891
Country: USA

Content:
  1. Early Life and Education
  2. Discovery of Jupiter's Moons and Asteroids
  3. Solar Activity Research
  4. Infrared Astronomy
  5. Other Contributions
  6. Honors and Recognition

Early Life and Education

Born and raised in rural Illinois, Seth Barnes Nicholson developed a passion for astronomy during his time at Drake University. In 1914, while observing at the Lick Observatory of the University of California, he discovered a newly found satellite of Jupiter, later named Pasiphae.

Discovery of Jupiter's Moons and Asteroids

Nicholson's dissertation in 1915 focused on calculating the orbit of Jupiter's moon, Pasiphae. He went on to discover several more satellites of Jupiter, including Sinope (1914), Lysithea and Carme (1938), and Ananke (1951). He also discovered the Trojan asteroid (1647) Menelaus.

Solar Activity Research

Throughout his career at Mount Wilson Observatory, Nicholson dedicated significant time to studying solar activity. He compiled annual reports on sunspot activity for a decade and participated in multiple solar eclipse expeditions to measure the brightness and temperature of the solar corona.

Infrared Astronomy

Collaborating with Edison Pettit in the early 1920s, Nicholson conducted pioneering infrared studies of celestial bodies. Their measurements of the Moon's infrared radiation suggested the presence of a thin layer of insulating dust on its surface. Similarly, their temperature measurements of red giants provided valuable insights into stellar diameters.

Other Contributions

In addition to his discoveries, Nicholson calculated the orbits of numerous comets and the dwarf planet Pluto. He served as editor and vice president of the Pacific Astronomical Society from 1943 to 1955 and was elected to the National Academy of Sciences.

Honors and Recognition

Nicholson's contributions earned him the Bruce Medal in 1963. Named in his honor are asteroid (1831) Nicholson, the lunar crater Nicholson, the Martian crater Nicholson, and a region on the moon Ganymede.

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