Jesse L. Greenstein, an astrophysicist whose many
accomplishments included seminal work on the nature of
quasars, died Monday, October 21, 2002, three days after
falling and breaking his hip. He was 93.

A native of New York City, Greenstein grew up in a family
that actively encouraged his scientific interests. At the
age of eight he received a brass telescope from his
grandfather — not an unusual gift for an American child,
but Greenstein soon was also experimenting in earnest
with his own prism spectroscope, an arc, a rotary spark,
a rectifier, and a radio transmitter. With the
spectroscope he began his lifelong interest in identifying
the composition of materials, a passion that would lead to
his becoming a worldwide authority on the evolution and
composition of stars.

Greenstein entered the Horace Mann School for Boys at the
age of 11, and by 16 was a student at Harvard University.
After earning his bachelor’s degree in 1929 and his
master’s in 1930, he decided that it would be prudent, in
the depths of the Great Depression, to join the family’s
real estate and finance business in New York. But by 1934
he was back at Harvard, earning his doctorate in 1937.

Greenstein won a National Research Council Fellowship in
1937, which allowed a certain amount of latitude in his
place of employment. With the stipend, he chose to join
the University of Chicago’s Yerkes Observatory at Williams
Bay, Wisconsin, remaining there for the duration of the
two-year fellowship. In 1939 he joined the University of
Chicago astrophysics faculty, and during the war years
did military research in optical design at Yerkes. He
also spent time at McDonald Observatory, then jointly
operated by the University of Chicago and the University
of Texas, before accepting an offer from the California
Institute of Technology to organize a new graduate
program in optical astronomy in conjunction with the
new 200-inch Hale Telescope at Palomar Observatory.

The Caltech astronomy program quickly became the premier
academic program of its kind in the world, with Greenstein
serving as department head from 1948 to 1972. During the
24-year period, he spent more than 1,000 observing nights
at Palomar and other major observatories, and also took
up radio astronomy in 1955. He was a staff member at Mount
Wilson and Palomar Observatories until 1979, when he
retired from the Caltech faculty, and remained active in
research for many years afterward. He stopped observing
in 1983, but continued research on white dwarfs, M dwarfs,
and the molecular composition of stars. Despite many
chances to become an administrator, he remained a
researcher for his entire life.

Greenstein’s research interests largely centered on the
physics of astronomical objects. In addition to stellar
composition, he also worked on the synthesis of chemical
elements in stellar interiors, studied the physical
processes of radio-emitting sources, worked with Caltech
colleague Maarten Schmidt on the high redshift of quasars
in 1963, demonstrated that quasars are quite compact
objects, and discovered and studied more than 500 white
dwarfs. In later years, he studied the magnetic fields
of white dwarfs, established their luminosities, and
worked on ultraviolet spectroscopy with data obtained
from the IUE satellite.

A common thread of his research endeavors, Greenstein wrote,
“was that they were pioneering thrusts, attempts to provide
first tests of a variety of physical laws under extreme
conditions in the inaccessible but convenient experimental
laboratories of the stars.”

Greenstein was active in the establishment of the National
Radio Astronomy Observatory, served as chair of the board
of the Association of University Research in Astronomy,
and was a former member of the Harvard Board of Overseers.
He also played a pivotal role in organizing various
national astronomical facilities, serving as chair of the
1970 decadal review of astronomy for the National Research
Council (for which the Greenstein Report was issued), and
served on the National Academy of Sciences’ committee on
science engineering and public policy.

He was elected to the National Academy of Sciences in 1957.

During his 72-year career in astrophysics, Greenstein
was named California Scientist of the Year in 1964, was
awarded the NASA Distinguished Public Service Medal in
1974, and the Gold Medal of the Royal Astronomical Society
in 1975. He was presented the Centennial Medal by Harvard,
and was named to the American Academy of Achievement in
1982.

He is survived by two sons, Peter Greenstein of Oakland,
California, and George Greenstein of Amherst, Massachusetts.
Naomi Kitay Greenstein, his wife of 68 years, whom he met
as a 16-year-old Harvard undergraduate, died earlier this
year. The Greensteins were often commended for the warmth
and hospitality they extended to astronomers throughout
the world. Naomi Greenstein also played a role in building
the spirit of the astronomy group at Caltech.