Biographical Memoirs Volume 86 (2005) / Chapter Skim
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Jesse Leonard Greenstein
Jesse Leonard Greenstein
Pages 162-187
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From page 162... ...
Archives Caltech of courtesy Wiener; Leigh by Photo
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, the nature of interstellar grains, the evolution of the chemical composition of stars, to the physical properties of white dwarfs provides the currently available fundamental knowledge of each of these fields. He was a leader of U.S.
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After his grandfather's death, Maurice, the oldest of nine children, assumed leadership of the business. As had his father before him, Maurice bought real estate in Brooklyn, as well as Manhattan, and he and the other members of the family eventually became quite prosperous.
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From page 165... ...
In the mid-1920s the program still retained its classical roots, with emphases on transit circles, navigation, and celestial mechanics, and it was not until 1928-1929 that Jesse came into contact with faculty members of the Harvard College Observatory, an administratively separate entity. There he learned of the new developments in astrophysics and galactic structure under the influence of such figures as the young Canadian theorist Harry Plaskett; Donald Menzel, whose interests were in solar physics, gaseous nebulae, and atomic processes; and especially Cecilia Payne, an English astronomer whose thesis "Stellar Atmospheres"Jesse described as "one of the great theses in astronomy." His undergraduate education was diffuse, but included a course in the philosophy of science and an introduction to what one of his professors termed the new fad of quantum mechanics.
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From page 166... ...
Although the work was monotonous, it convinced Jesse that his real love was astronomy, not the attempt to make money in the real estate business, even though by 1934 he had already made a very lucrative real estate deal. Jesse, now confident of his future course, returned to Harvard graduate school, despite the warning of Harlow Shapley, the Harvard College Observatory director, that astronomy had changed too much forJesse to catch up.
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From page 167... ...
On the basis of low-resolution objective prism spectra obtained with the resident Harvard 24-inch telescope,Jesse measured photographically the energy distributions of little and greatly reddened B-type stars (difficult to do accurately with the techniques available in the 1930s) , and showed not only that absorption by dust followed a V° 7 law but also that the slope was essentially independent of the choice of interstellar cloud (i.e., the law appeared to be universal)
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From page 168... ...
, butJesse and Fred Whipple found it exciting and tried to explain it using the best theoretical notions of the time. In addition, Jesse's recognition of the new world opened up by this discovery was the spark that ignited his support of radio astronomy at Caltech some 20 years later.
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From page 169... ...
Stimulated by a late-night brainstorming session with Struve, the two young researchers built a Yerkes nebular spectrograph of unusual fast design, which—jerrybuilt for the 40-inch refractor—nevertheless yielded spectacular spectra of the earth's aurora. An improved version of the design was transferred later to a mountainside at the McDonald site and used subsequently by Struve and Stromgren to discover what Stromgren later called "H 11 regions." Meanwhile, Greenstein and Henyey employed a novel Fabry photometer on the 40-inch and discovered diffuse galactic light, the scattering of light from stars produced by dust clouds in the Milky Way, along lines of sight far from the stars themselves.
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From page 170... ...
Transition probabilities came from theory and/or solar line strengths, something of a grab bag, even though the source of solar continuous opacity, H-, had by then been identified. The fact that upsilon Sagittarii did not conform to the expectation that stellar abundance ratios were universal was a major breakthrough in what would become, in the years following World War 11, the idea of galactic chemical evolution.
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From page 171... ...
The two of them produced a number of OSRD reports on military applications of optical design, with titles such as "Unit Power Periscopes," "Tank and Anti-Tank Telescopes," and "WideField Fast Cameras." Working with strange glasses, developing new methods of ray tracing, as well as dealing with industrial and military personnel, were new experiences for Jesse. As a junior Yerkes staff member he did not participate in administrative decisions, but the war work initiated him into the world of committee meetings and the responsibilities of management.
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His output expanded to more than 400 papers by the end of his active career in the early 1990s. Jesse, who was almost immediately advanced to the rank of full professor, began teaching stellar atmospheres and interiors to physics and new astronomy graduate students, and took up the task of recruiting astronomy faculty.
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Wilson and Palomar Observatories, had completed construction of the innovative 200-inch coude spectrograph, and using this instrument Jesse returned to the study of relative abun
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Fowler of the Caltech Kellogg Radiation Lab, as well as the 1956 predictions of the stellar origin of the heavy elements by Fowler and colleagues Fred Hoyle and Margaret and Geoffrey Burbidge,Jesse obtained funding from the Air Force Office of Scientific Research for the famous Abundance Project, which spanned the period from 1957 to 1970. The grant supported Jesse's observational program with the coude spectrograph and also a substantial analysis team of graduate students and postdocs, many of whom became prominent figures in today's astronomical world.
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From page 175... ...
An these results provided the observational testing ground for theories both of stellar structure and evolution and for scenarios on the origin of the chemical elements in the post-big-bang era. RADIO ASTRONOMY, QSOS Harking back to his 1937 collaboration with Fred Whipple in the abortive attempt to explain Jansky's newly discovered radio noise,Jesse retained his fascination with radio astronomy
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Jesse's interest in radio astronomy soon crossed paths with another of his new interests—faint blue stellar objects— in an unexpected way. Stars with very blue colors were known to be a varied lot; some were halo horizontal branch stars, others white dwarfs, and still others cataclysmic variables such as old novae.
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From page 177... ...
As Jesse himself has noted, the "logjam was broken." In a landmark paper Greenstein and Schmidt (1964) discussed the physics of the emitting region in these two objects, rejected the notion that gravitational redshifts could explain what was seen, produced evidence in support of the idea that the redshifts were cosmological, and noted the impossibility of a nuclear energy source as an explanation of the extraordinarily high luminosities required.
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In more than 60 papers spread during 20 years Jesse explored such additional topics as surface composition, energy distribution, line profiles, magnetic fields, rotation, gravitational diffusion, and cooling theory for white dwarfs. Accurate energy distributions plus models led to an accurate temperature scale.
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Space does not permit an exhaustive listing, but a few of the important ones follow. He was a member of the Committee on Science and Public Policy of the National Academy of Sciences, advised NASA on such matters as the scientific management of the Space Telescope (which ultimately led to the establishment of the Space Telescope Science institute)
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At one point the panel members had a serious disagreement over the I ecolulller dation for the next large radio astronomy facility Caltech, MIT ar d the National Radio Astronomy Observatory (NRAO) all had plans, they were mutually exclusive, and no ore would give ir Jesse demanded that the par el pick ore ir strumer t for the Report, ar d fir ally we picked the NRAO proposal, which later was fur ded ar d became the VLT, an extremely important telescope in this processJesse was above institutional concerns, and while he would have been pleased if the Caltech proposal had been chosen, he did not push me or the Caltech proposal in this ar d other ways, he was a r atior al server t HONORS AND HONORIFIC OFFICES In recognition of his scientific accomplishments and services to astronomy, Jesse was elected to many scholarly organizations including the National Academy of Sciences (in 1957)
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Honors included the California Scientist of the Year award in 1964, the Henry Norris Russell Lectureship of the American Astronomical Society in 1970, the Bruce Medal of the Astronomical Society of the Pacific in 1971, the NASA Distinguished Public Service Medal in 1974, and the Gold Medal of the Royal Astronomical Society in 1975. He received an honorary D.Sc.
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. He was especially fond of the old nova called WZ Sagittae, because its spectrum contained not only the characteristic hydrogen emission lines but also the absorption lines of a white dwarf.
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Wilson and Palomar astronomers to support the work of, and suitable accommodations for, female astronomers at the telescopes, significant progress into what had been an exclusively maleoriented club. A man of wide cultural interests, Jesse loved classical music, particularly the chamber music of Mozart and Schubert, and especially the late quartets of Beethoven.
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In this era of multiauthored papers occasionally numbering in scores, he was virtually the last of a vanishing breed, representing a style no longer much with us: the single astronomer alone on a dark night in a cramped telescope cage, exposed and cold, in a personal confrontation with God, or Nature, or the Truth, or whatever you may choose to call it. I AM INDEBTED TO George Greenstein for valuable family information and to Peter Greenstein for access to his father's extended personal memoir.
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From page 185... ...
The polarization of starlight by interstellar dust particles in a galactic magnetic field.
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The quasi-stellar radio sources 3C 48 and 3C 273. Astrophys.
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From page 187... ...
The nature of faint blue stars in the halo. Astrophys J 28(suppl.)
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