Edwin Salpeter, at 83; helped determine birth, death rates of stars

EDWIN E. SALPETER

ITHACA, N.Y. - Edwin E. Salpeter, an astrophysicist cited for studies of chain reactions in stars, including the "Salpeter-Bethe equation" describing how helium changes to carbon, has died. He was 83.

A professor emeritus of physical sciences at Cornell University, Dr. Salpeter had leukemia and died Tuesday at his home in Ithaca, the university said.

Born in Austria, Dr. Salpeter moved to the Ivy League school in 1949 as a postdoctoral student and spent his career there. Although he retired in 1997, he continued to publish papers and moved into new arenas of research, including explorations of neuromuscular disorders and the epidemiology of tuberculosis.

A self-deprecating man with an infectious grin, Dr. Salpeter was admired for his intuitive powers and his ability to visualize abstract concepts. He described his mind as "quick but sloppy" in saying he preferred the challenge of tackling a new problem to undertaking mathematical calculations.

"Ed's contributions to astrophysics revolutionized whole subfields," said Saul Teukolsky, a longtime colleague and chairman of Cornell's physics department. "And yet no matter how eminent he became, Ed retained his humility and sense of fun. . . . It was truly a delight to spend time with him."

Along with Hans Bethe, a theoretical physicist at Cornell who received a Nobel Prize in physics in 1967, Dr. Salpeter introduced an equation in 1951 showing how helium nuclei fuse to form carbon in the interiors of ancient stars. Until then, the origin of elements beyond helium in the periodic table was a mystery.

From that work, Dr. Salpeter determined the formation rates of stars of different masses in the galaxy. The process remains the basis of today's studies into the rates of stellar births and deaths.

In 1964, while working independently, Dr. Salpeter and Soviet physicist Yakov Zeldovich were the first to propose that a stream of gas falling toward a black hole could in principle be heated to very high temperatures, where it would produce detectable X-rays. Thirty years later, data from the Hubble telescope confirmed his idea. "It's good to finally win the bet," Dr. Salpeter said at the time.

In 1997, Dr. Salpeter and Sir Fred Hoyle, a British scientist who coined the term "Big Bang," shared the $500,000 Crafoord Prize from the Royal Swedish Academy of Sciences for "their pioneering contributions involving the study of nuclear reactions in stars and stars' development."

The prize is given annually to mark accomplishments in fields not covered by the Nobel Prizes in science, whose winners are also chosen by the academy.

Late in his career, research by Dr. Salpeter and his wife, Miriam, a specialist in cell biology, contributed to the understanding and treatment of neuromuscular disorders such as myasthenia gravis. His wife, a neurobiologist, died in 2000.