Jesse Leonard Greenstein (October 15, 1909 – October 21, 2002) was an American
astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...
. His parents were Maurice G. and Leah Feingold.
He earned a Ph.D, with thesis advisor
Donald H. Menzel
Donald Howard Menzel (April 11, 1901 – December 14, 1976) was one of the first theoretical astronomers and astrophysicists in the United States. He discovered the physical properties of the solar chromosphere, the chemistry of stars, the atmosp ...
, from
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of highe ...
in 1937, having started there at age 16. Before leaving Harvard, Greenstein was involved in a project with
Fred Lawrence Whipple
Fred Lawrence Whipple (November 5, 1906 – August 30, 2004) was an American astronomer, who worked at the Harvard College Observatory for more than 70 years. Amongst his achievements were asteroid and comet discoveries, the " dirty snowball" h ...
to explain
Karl Jansky
Karl Guthe Jansky (October 22, 1905 – February 14, 1950) was an American physicist and radio engineer who in April 1933 first announced his discovery of radio waves emanating from the Milky Way in the constellation Sagittarius. He is considered ...
's discovery of
radio wave
Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz ( GHz) and below. At 300 GHz, the corresponding wavelength is 1 mm (sho ...
s from the
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. ...
and to propose a source. He began his professional career at
Yerkes Observatory
Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 to 2018. Owner ...
under
Otto Struve
Otto Struve (August 12, 1897 – April 6, 1963) was a Russian-American astronomer of Baltic German origins. In Russian, his name is sometimes given as Otto Lyudvigovich Struve (Отто Людвигович Струве); however, he spent most o ...
and later went to
Caltech
The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...
. With
Louis G. Henyey he invented a new
spectrograph
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify mate ...
and a
wide-field camera. He directed the Caltech astronomy program until 1972 and later did classified work on military
reconnaissance satellite
A reconnaissance satellite or intelligence satellite (commonly, although unofficially, referred to as a spy satellite) is an Earth observation satellite or communications satellite deployed for military or intelligence applications.
Th ...
s.
With
Leverett Davis, Jr, he demonstrated in 1949 that the magnetic field in our galaxy is aligned with the spiral arms. His theoretical work with Davis was based on the conclusion just reached by
William A. Hiltner that the recently detected polarization of starlight was due to scattering off interstellar dust grains aligned by a magnetic field.
Greenstein did important work in determining the abundances of the
elements in stars, and was, with
Maarten Schmidt
Maarten Schmidt (28 December 1929 – 17 September 2022) was a Dutch-born American astronomer who first measured the distances of quasars. He was the first astronomer to identify a quasar, and so was pictured on the March cover of ''Time'' mag ...
, among the first to recognize
quasar
A quasar is an extremely luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a mass rangi ...
s as compact, very distant sources as bright as a galaxy. The spectra of the first quasars discovered, radio sources
3C 48
3C48 is a quasar discovered in 1960; it was the second source conclusively identified as such.
3C48 was the first source in the Third Cambridge Catalogue of Radio Sources for which an optical identification was found by Allan Sandage and Thoma ...
and
3C 273
3C 273 is a quasar located in the constellation of Virgo. It was the first quasar ever to be identified.
It is the optically brightest quasar in the sky from Earth ( m ~12.9), and one of the closest with a redshift, ''z'', of 0.158. A lumino ...
, were displaced so far to the red due to their
redshifts
In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...
as to be almost unrecognizable, but Greenstein deciphered 3C 48 shortly before Schmidt, his colleague at the
Hale Observatories The Hale Observatories are observatories set up by George Ellery Hale, including:
* Mount Wilson Observatory, in Los Angeles County, California
* Palomar Observatory, in San Diego County, California
* Yerkes Observatory, in Williams Bay, Wisconsi ...
worked out the spectrum of 3C 273.
Honors
Awards
*
Henry Norris Russell Lectureship The Henry Norris Russell Lectureship is awarded each year by the American Astronomical Society in recognition of a lifetime of excellence in astronomical research. The idea for the lectureship came from then society President Harlow Shapley in 1945, ...
of the
American Astronomical Society (1970)
*
Bruce Medal
The Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was fi ...
(1971)
*
Gold Medal of the Royal Astronomical Society
The Gold Medal of the Royal Astronomical Society is the highest award given by the Royal Astronomical Society (RAS). The RAS Council have "complete freedom as to the grounds on which it is awarded" and it can be awarded for any reason. Past awar ...
(1975)
*Golden Plate Award of the
American Academy of Achievement
The American Academy of Achievement, colloquially known as the Academy of Achievement, is a non-profit educational organization that recognizes some of the highest achieving individuals in diverse fields and gives them the opportunity to meet ...
(1980)
Honors
* Elected to the
American Academy of Arts and Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...
(1954)
* Elected to the United States
National Academy of Sciences (1957)
* Elected to the
American Philosophical Society
The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...
(1968)
Named after him
*
Asteroid 4612 Greenstein
References
External links
Obituary from CaltechCaltech oral history interview
{{DEFAULTSORT:Greenstein, Jesse
1909 births
2002 deaths
American astronomers
Jewish astronomers
Harvard University alumni
California Institute of Technology faculty
Recipients of the Gold Medal of the Royal Astronomical Society
Members of the American Philosophical Society