Tucson notable: Astronomer Bart Bok studied the Milky Way

Astronomer compiled world's Milky Way data

By Steve Williams
The Arizona Daily Star

Observations of our galaxy in the last decade have revealed what Tucson astron omer Bart Bok calls "a bigger and better Milky Way."

They have shown that the galaxy's diameter is three to five times what it was thought to be just seven or eight years ago, and the galaxy's mass is three to six times what it was believed to be, Bok said in a recent interview.

The 76-year-old distinguished scientist, who retired as head of the UA astronomy department in 1974, is considered the world's top expert on the Milky Way.

He reviewed recent research on the galaxy Jan. 10 in his keynote speech to a meet­ing of the American Astronomical Society in Boston.

His talk was called the Russell Lecture, a speech given every year by the winner of the Henry Norris Russell Prize. Bok is this year's recipient of the award for outstand­ing astronomical research.

Just eight years ago, astronomers thought the edge of the galaxy was about 60,000 light years from the center, Bok said. A light year is about 6 trillion miles. But new observations show that the galaxy's radius is about 250,000 light years, he said.

Estimates of the mass of the galaxy have climbed from 200 billion times the mass of our sun to 2 trillion solar masses in the last few years, he said.

"It's a big bowl of jelly we're floating in," Bok said.

Since his retirement freed him from ad­ministrative and teaching duties, Bok said, he has devoted most of his time to coordina ting worldwide research on the Milky Way.

''I feel I retired at a very critical time when exciting discoveries were being made and someone was needed to put it all to gether," Bok said.

"Astronomers all over the world let me know what they're doing in Milky Way research, and I let everyone know what every­one else is doing, and it's all tied together very nicely."

In 1973, Bok and his late wife, astronomer Priscilla Bok, wrote a fourth edition of their book "The Milky Way."

"We hoped that edition would be good for 15 years or so," Bok said. "But by '77 or '78, it became clear the new edition was out of date already, so I began working on a new edition, which was published in 1981.

"Things seem to have settled somewhat now, so the fifth edition should be good for a while."

UA's Bok dies; was top expert on Milky Way

Bart J. Bok, an astronomer regarded as the world's leading expert on the Milky Way galaxy, died yes­terday in his Tucson home of an ap­parent heart attack. He was 77.

Bok, the author of several books, had spent the years since his 1974 retirement as head of the University of Arizona astronomy department coordinating worldwide research on the Milky Way.

The fifth edition of his book "The Milky Way" was published in 1981.

Bok, professor emeritus of astron­omy and former director of the UA Steward Observatory, came to the UA in 1966 from Canberra, Australia, where he had been director of the Australian National University's Mount Stromlo Observatory for nine years.

He also taught at Harvard University and served as associate director of its observatory from 1946 to 1952. He was a native of Holland.

Bok recently went to Java, where he lectured and observed the June 10 total eclipse of the sun.

After that, he wrote friends at the UA, saying he was "off to Europe for a two-month tour of conferences, symposia, lectures and colloquia."

Bok pioneered research in accurate measurement of the colors and brightness of southern stars and in cataloging and assessing the incandescent hydrogen clouds in the southern Milky Way.

His more than 100 professional publications included several books in addition to the five editions of "The Milky Way."

"The Distribution of Stars in Space," and "The Astronomer's Universe" were among the titles.

In 1978, four years after his retire­ment from the UA, Bok was awarded an honorary doctor of science de­gree from the university. He had been elected to the National Acad­emy of Sciences 10 years earlier.

He was the 1983 recipient of the Henry Norris Russell prize for out­ standing astronomical research.

Shortly after his retirement, Bok told an interviewer that he began studying astronomy as a Boy Scout patrol leader in The Netherlands, literally getting shamed into the study by a Scoutmaster.

"I got ashamed of myself," when the Scoutmaster brought attention to his lack of knowledge of the stars, he said. "I went out and got a little book on the stars, started studying it and saved money to get a tele­scope."

His career included service as president of the American Astronomical Society and president of the International Astronomical Union's commission on the structure and dy­namics of the galactic system. He also was a fellow of the Royal Astronomical Society.

He received his doctoral degree from the University of Groningen in The Netherlands and became a naturalized citizen of the United States in 1938.

Bok is survived by a son, John, of Boston, and a daughter, Joyce Ambruster, of Racine, Wis.

Funeral services have not been scheduled.