Cornell astrophysicist Edwin Salpeter dies at 83

ITHACA, N.Y. (AP) -- Edwin E. Salpeter, an astrophysicist whose work in the "Salpeter-Bethe equation" showed how helium changes to carbon, has died. He was 83.

Salpeter had leukemia and died Tuesday at his Ithaca home, said Cornell University, where he had been a professor emeritus of physical sciences.

The Austrian-born Salpeter attended the school in 1949 as a postdoctoral student and spent his career there. Although he retired in 1997, he continued to publish papers and conduct research, including explorations of neuromuscular disorders and the epidemiology of tuberculosis.

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

In 1951, Salpeter and Cornell theoretical physicist Hans Bethe, winner of the 1967 Nobel Prize in physics, introduced an equation 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, Salpeter determined the formation rates of stars of different masses in the galaxy. It remains the basis of studies into the rates of stellar births and deaths.

In 1964, while working independently, Salpeter and Soviet physicist Yakov Zeldovich were the first to propose that a stream of gas falling toward a black hole could be heated to produce detectable X-rays. Thirty years later, data from the Hubble telescope confirmed his idea.

"It's good to finally win the bet," Salpeter said at the time.

In 1997, 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 work in the study of nuclear reactions in stars.

The annual prize marks accomplishments in scientific fields not covered by the Nobel Prizes, whose winners also are chosen by the academy.

Salpeter is survived by his wife, Lhamo; daughters Judy and Shelley, and four grandchildren.

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