Janet A. Mattei, astronomer with a passion for flowers; 61

For 30 years, Janet Akyuz Mattei was the lodestar for amateur astronomers tracking the skies for diamond-like stars whose brightness waxes and wanes.

As an astronomer, Dr. Mattei was internationally known for her knowledge of variable stars -- the ones that pulsate, expand, and contract -- and as director since 1974 of the American Association of Variable Star Observers in Cambridge. As such, she was in charge of compiling and analyzing data on 40,000 or so variable stars that was sent in by some 1,300 observers in 40 countries.

Dr. Mattei, 61, of Littleton, died March 22 at Brigham and Women's Hospital of acute myelogenous leukemia.

"Janet gave off light like a star, herself," said Elizabeth O. Waagen, interim director of the astronomy group. "She gave off so much positive energy, you couldn't help but be glad for the chance to have met her."

As director of the association, Dr. Mattei "was responsible for the quality control of over 450,000 observations a year submitted by observers, mostly amateur astronomers, worldwide," Waagen said.

Dr. Mattei was not interested only in the mathematical implications of a twinkling star. She was also fascinated by its effect on people who discovered it. "To me, an observation of a variable star is not a number, not a statistic" Dr. Mattei said in a Sky & Telescope magazine interview in December. "It's something very much alive. I see the estimate and imagine the observer's face light up as he or she looks at the star through a telescope."

She played a key role in getting NASA to give observation time on the Hubble space telescope to amateur astronomers.

Much of Dr. Mattei's work was in classrooms, where she provided guidance in setting up more than 200 observation programs for student science projects. She was a principal investigator of two NASA-funded grants and co-director of another educational program funded by the National Science Foundation, Waagen said.

Born in Bodrum, Turkey, Dr. Mattei was considered brilliant by her teachers. While she was attending the American High School in Izmir, some teachers suggested she go into science, particularly astronomy.

In 1962, she came to this country under a full Wien Scholarship for international students and studied at Brandeis University, where she graduated in 1965. "I still didn't know what do with my life," Dr. Mattei told Sky & Telescope, "so I worked at Beth Israel Hospital for a year and a half, running its cardiopulmonary laboratory."

Dr. Mattei returned to Turkey in 1967 to teach physics and mathematics and then to pursue a master's degree at Ege (Aegean) University. There she heard about the Maria Mitchell Observatory in Nantucket.

At the observatory, women were encouraged to go into astronomy, then largely a male bastion. Its director was Dr. Dorrit Hoffleit, an astronomer based at Yale University, who became Dr. Mattei's mentor.

Dr. Mattei interrupted her studies at Ege and arrived on Nantucket in 1969. There, she later told Sky & Telescope, "Dorrit's decision to hire me as her assistant changed my life."

"Janet was a brilliant young woman," Hoffleit, 97, recalled by phone this week. "She will be a very difficult person to replace at the AAVSO."

After her summer on Nantucket, Dr. Mattei returned to Turkey to complete her master's degree, and then worked as a teaching assistant at the Hayden Planetarium in New York in 1971. She earned a second master's degree in astronomy from the University of Virginia in 1972.

That year, Dr. Mattei was named assistant to the director at the astronomy association and married Michael Mattei, who was working at the Harvard Observatory. Dr. Mattei earned her doctorate from Ege in 1982.

Dr. Mattei and her husband went on many scientific trips together, among them to see the solar eclipse in Kenya in 1973.

She loved flowers, and that interest took her to the tops of many mountains in search of rare species. Her husband said she once climbed to the top of Table Mountain outside Cape Town, South Africa, just to see a flower that grows only there. She also climbed in the Alps in Italy and Switzerland for the same reason. "She photographed [flowers] wherever she traveled and would make prints of them or cards for friends," Waagen said. Many of Dr. Mattei's flower photographs over the last five years were from Hawaii, where she taught science teachers to educate another generation about variable stars.

Before her illness was diagnosed in September, she and her husband had planned a trip to see the desert flowers of Arizona.

A sign in her office reads: "Stars are the flowers of the universe, and flowers are the stars of the earth."

Besides her husband, Dr. Mattei leaves her mother, Bulisa Akyuz of Izmir; two brothers, Yusef Akyuz of Sudbury and Hayim Akyuz of Izmir; and two sisters, Kadem Senkal of Istanbul and Beki Notrika of Tel Aviv. Funeral services were held at Temple Emanuel in Lowell. Burial was at Mt. Auburn Cemetery. A memorial service is planned.