Awards and Honors
Astronomical Society of the Pacific awards
highest honor to astronomer Robert Kraft
By Françoise Chanut
The Astronomical Society of the Pacific has awarded the 2005
Catherine Wolfe Bruce Gold Medal to Robert P. Kraft, professor
emeritus of astronomy and astrophysics and former director of
the UC Observatories/Lick Observatory (UCO/Lick). Kraft is the
sixth astronomer associated with the Lick Observatory to receive
this award, and the fourth associated with UCSC.
Robert Kraft
UCSC Photo Services
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The Bruce Medal is the highest honor bestowed by the Astronomical
Society of the Pacific (ASP). It recognizes scientists worldwide
for fundamental and lifelong contributions to the field of astronomy.
Previous recipients include many renowned astronomers, such
as 1938 medalist Edwin P. Hubble, who showed the universe is
expanding, and 2003 medalist Vera Rubin, who demonstrated the
existence of dark matter.
Kraft has received many awards in his long and distinguished
career, but he said the Bruce Medal holds special significance.
"The Bruce Medal I cherish the most since it has the longest
history and is given on a worldwide basis," Kraft said.
"The list of recipients contains a lot of my heroes, such
as Otto Struve and Jesse Greenstein, and I feel really honored
to be on that list."
In announcing the award, the ASP acknowledged Kraft's outstanding
research achievements and extensive service to the astronomy
community.
Kraft served as director of UCO/Lick from 1981 to 1991. During
this time he played a key role in bringing about the W. M. Keck
Observatory on Mauna Kea, Hawaii, by committing the resources
of Lick Observatory to the construction and instrumentation
of the world's first 10-meter telescope, now known as Keck I.
Keck I and its twin, Keck II, remain the largest optical and
infrared telescopes ever built. UCO/Lick operates the Keck Observatory
in cooperation with Caltech and NASA.
Kraft also served as president of the American Astronomical
Society from 1974 to 1976 and president of the International
Astronomical Union from 1997 to 2000.
As a researcher, Kraft made important contributions to the
understanding of novae, stars that undergo a sudden increase
in brightness due to massive nuclear explosions. He showed that
all novae arise from close binary star systems in which the
more evolved star (usually a white dwarf) siphons up hydrogen
and helium from its expanding companion. The transferred material
forms a disk whose rapid accretion onto the dense white dwarf
leads to an explosion. Kraft also established an important rung
on the ladder of celestial distances by assessing the contribution
of interstellar dust to the dimming of Cepheid variables in
the disk of our galaxy. His work on stellar rotation--now a
fundamental topic in astronomy textbooks--showed that stars
like the Sun spin slower and slower as they age because winds
of charged particles carry away their angular momentum.
Kraft became interested in the chemical composition of stars
after observing an unusual star named FG Sagittae, which underwent
rapid changes in composition and later nearly disappeared behind
a cloud of its own soot. He went on to analyze in detail the
chemical composition of the oldest stars in our galaxy. This
work led to several major contributions, including evidence
for deep mixing of elements in red giants, bloated stars at
a late stage of their evolution. He also established intriguing
differences between the chemical composition of stars in globular
clusters and their neighboring field stars.
Kraft, 77, earned his B.S. and M.S. in mathematics from the
University of Washington and his Ph.D. in astronomy from UC
Berkeley. He rose to prominence in the 1960s as an astronomer
at the Mt. Wilson and Palomar Observatories in Pasadena. He
joined UC Santa Cruz in 1967 as an astronomer at Lick Observatory
and professor of astronomy and astrophysics, after holding assistant
professor positions at Indiana University and the University
of Chicago.
Soon after joining UC Santa Cruz, Kraft was elected to both
the National Academy of Sciences and the American Academy of
Arts and Sciences. In 1995, the American Astronomical Society
named Kraft the Henry Norris Russell Lecturer for his lifetime
achievement in astronomy. Kraft's work currently focuses on
the abundance of rare earth elements in globular clusters.
The Astronomical Society of the Pacific was founded in San
Francisco in 1889 and has awarded the Catherine Wolfe Bruce
Gold Medal most years since 1898. From the outset, the medal
was meant for astronomers of any nationality and either gender,
and might only be awarded when a suitable candidate was found.
The ASP board of directors selects a medalist among candidates
nominated each year by the directors of six observatories--three
in the United States and three elsewhere in the world. Additional
information on the Astronomical Society of the Pacific is available
the web at http://www.astrosociety.org.
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