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Jesse Leonard GreensteinAmerican astronomer
Date of Birth: 15.10.1909
Country:  USA |
Content:
- Jesse Leonard Greenstein
- Research at Yerkes and McDonald Observatories
- Academic Career at Caltech
- Stellar Spectroscopy and Galactic Studies
- Interstellar Polarization and Radio Astronomy
- Honors and Recognition
Jesse Leonard Greenstein
Early Life and EducationJesse Leonard Greenstein was born in New York City in 1909. He graduated from Harvard University in 1929 and subsequently pursued business endeavors. However, his passion for astronomy led him to continue studying at Harvard from 1934 to 1937.
Research at Yerkes and McDonald Observatories
Greenstein worked at the Yerkes Observatory from 1937 to 1948 and also at the McDonald Observatory from 1939 to 1948. During this period, he investigated various aspects of astrophysics, including the interaction of radiation with matter in interstellar space, interstellar absorption, and the reddening of starlight.
Academic Career at Caltech
In 1948, Greenstein joined the staff of the Mount Wilson and Mount Palomar Observatories. He also became a professor at the California Institute of Technology (Caltech) in 1949.
Stellar Spectroscopy and Galactic Studies
Greenstein focused his research on stellar spectroscopy, particularly the chemical composition of stellar atmospheres. He determined the chemical and isotopic composition of numerous normal and peculiar stars. This work formed part of a larger program he developed with William A. Fowler to study the formation and evolution of chemical elements through comparative stellar spectroscopy.
Greenstein also conducted extensive spectroscopic observations of degenerate stars and developed a spectral classification scheme for white dwarf stars. He determined their temperatures, radii, and masses.
Interstellar Polarization and Radio Astronomy
In the 1950s, Greenstein proposed a mechanism for the origin of interstellar polarization in the light of stars due to the preferential alignment of dust particles by the interstellar magnetic field (the Davis-Greenstein mechanism). He participated in early efforts to optically identify star-like radio sources (quasars), study their spectra, and explain the redshift phenomenon.
Honors and Recognition
Greenstein was elected a member of the National Academy of Sciences in 1957 and the Royal Society of Belgium in Liege. He received the Bruce Medal of the Pacific Astronomical Society (1971), the Gold Medal of the Royal Astronomical Society (1975), and the Medal of the University of Liege (1975). An asteroid, 4612 Greenstein, is named in his honor.
