Her Story 2015

Astronomer has seen major achievements for space research, women in science

Catherine Pilachowski is using tools next to a large telescope
Catherine Pilachowski

Growing up during the Space Race, Catherine Pilachowski remembers being swept up in the excitement of the spaceflight competition between the United States and the Soviet Union.

She didn't care that space exploration was a male-dominated field, or that her male classmates sometimes received more credit than her from teachers. At her mother's encouragement, a teenage Pilachowski began reading books about science and became deeply interested in astronomy -- particularly the evolution of stars.

"I knew then that I wanted to be an astronomer," she said. "I was fascinated by the idea that I could use the light emitted by stars to study how they change over time."

Pilachowski, now a professor and Kirkwood Chair in astronomy at Indiana University Bloomington, has brought that passion and more to her work at IU, where she researches the history of the Milky Way galaxy by studying the chemical composition of globular star clusters.

For a long time, Pilachowski said, these massive star clusters were thought to be composed of stars from a single burst of star formation, held together by gravity, moving like a swarm of bees. But in recent years, astronomers have discovered globular clusters are complex, with multiple bursts of star formation and a range of star ages, chemical properties and movement patterns.

While at IU, Pilachowski and her former graduate students Maria Cordero and Christian Johnson found that stars with unusual chemical compositions concentrate in the centers of clusters, telling evidence of the clusters' complex formation processes.

And because of the speed at which light travels, when Pilachowski points her telescope toward stars in far-away galaxies, she's essentially looking back in time.

"We're seeing galaxies in process of formation, 10 or more billion years ago," she said. "Stars change very slowly, but the universe of 13 billion years ago was very different from today."

The image of the Kitt Peak national observatory infrared telescope shown here contains numbered icons that indicate the movement of light through the device. The yellow line in the image illustrates the trajectory of light.

The numbered icons indicate the following: 1. Light from a distant star enters the top of the telescope as parallel rays of light. 2. The primary mirror at the bottom of the telescope reflects the starlight upward to a second mirror that reflects the light down through a hole in the primary mirror. 3. The beam of starlight finally focuses in the infrared spectrometer "Phoenix," which operates at a temperature of -430 Fahrenheit. 4. Phoenix disperses the light into a spectrum and records it on an infrared array detector.

Kitt Peak Infrared telescope

Another thing she says looks very different today than years ago is the involvement of women in astronomy.

"Astronomy as a field has been an amazing success story," Pilachowski said. "During my career, I've seen the number of women in my field increase from 10 percent to about 30 or 40 percent."

She estimates that nationwide women currently make up about 10 percent of senior astronomy faculty members, 20 to 30 percent of new faculty members, 30 to 40 percent of graduate students and 50 percent of undergraduate students -- a definite upward trend.

In fact, three of Pilachowski's last four graduate students were women. And she said IU's astronomy department, though one of the smallest with a doctoral program in the country, has one of the highest percentages of female tenured faculty members: 50 percent.

"Women make great astronomers," Pilachowski said. "It's a very collaborative field, so astronomers need to be comfortable sharing their findings -- and telescope time -- with others."

She said her IU colleagues have also said the increase in women faculty members has improved personal relationships within the department. Women seem to be more willing to pitch in when things need to be done and often put the good of the department before their individual ambitions, she said.

In addition to her research, Pilachowski has held several leadership positions in the astronomical community, helping to raise the profile of IU's astronomy department. She has served on numerous national and international boards and committees, is a fellow of the American Association for the Advancement of Science and served as president of the American Astronomical Society from 2002 to 2004.

But she plays an important role in the IU community as well. Since coming to IU in 2001 as the inaugural Daniel Kirkwood Chair in Astronomy, she has served as chair of the Department of Astronomy, interim dean of women's affairs and associate dean of the IU College of Arts and Sciences. And as an astronomy faculty member, she and her colleagues teach nearly one-third of IU undergraduate students, who choose astronomy to fill their science course requirements.

"This is a great responsibility because we have a huge impact on people's perception of the sciences, how people look at science," she said.

And, hopefully, she said, have a huge impact on female students' decisions to pursue careers in science.

Left: Pilachowski outside the Kirkwood Observatory. Top right: A stained glass mosaic of one of the telescopes at Kitt Peak in Arizona, made by Pilachowski's mother, hangs in her office. Bottom right: A view of Pilachowski's office.