While the total eclipse will darken Indiana skies during the solar eclipse April 8, it will also shine a spotlight on the Indiana University Bloomington campus. And the brightest of that light will fall upon the campus’s resident sky experts: the faculty and students in the College of Arts and Sciences’ Department of Astronomy.
Home to one of only about 30 dedicated astronomy departments in the country, IU Bloomington has a long history in the field. One of the university’s founding faculty members, Theophilus Wylie, taught astronomy to the first graduating class of 1830. Another early faculty member, Daniel Kirkwood, was a mathematician who discovered the “Kirkwood Gaps,” the empty spaces in our solar system’s asteroid field.
The department’s current impact is partly a consequence of this early foundation in astronomy, said Caty Pilachowski, department chair and IU Distinguished Professor of Astronomy. Despite being one of the smallest Ph.D.-granting departments in the country, it has a powerful research record.
“Because we’re a small department, we’re very focused, very specialized,” Pilachowski said. “This is evident in our research output and its impact.”
The major strength of the Department of Astronomy is stellar and extragalactic astrophysics — a continuation of the mathematical legacy of Kirkwood, she said. This includes research on star formation in galaxies, and on stars and star clusters, as well as the physics of other astronomical phenomena, such as the role of black holes in preventing star formation in galaxies.
Exoplanetary science
The department has also recently expanded into the rapidly growing field of exoplanet astronomy, or the study of planets around stars other than our sun. These planets, which were completely unknown less than 30 years ago, currently number over 5,000.
Among IU’s contributions to exoplanetary science is research by Songhu Wang, an assistant professor of astronomy. His work has revealed strong evidence that exoplanets like the first ever discovered — a Jupiter-like world circling remarkably close to its star — are not as isolated a phenomenon as previously thought. The department has also recently welcomed Cristobal Petrovich, an astronomer who researches the formation of exoplanets. Petrovich joined IU as a part of the Faculty 100 initiative.
High-performance computing
Another area in which the Department of Astronomy excels is the use of high-performance computing.
Using this technology to understand astronomical phenomenon dates to Marshal Wrubel’s pioneering use of high-performance computers to model stellar atmospheres, Pilachowski said. A professor of astronomy, Wrubel was the founder of IU’s Computing Research Center, established in 1955 and originally located in the basement of Swain Hall West.
“High-performance computing really started to get serious around this time,” Pilachowski said. “Wrubel was one of the first people to use high-performance computers to create realistic models of stellar atmospheres — the layers of gas around stars through which light passes — to calculate their spectrum.”
The Department of Astronomy remains one of the top users of IU’s high-performance computing capabilities, including the Big Red 200 supercomputer, said Scott Michael, director of software and solutions at University Information Technology Services’ Research Technologies. In fact, IU researchers’ easy access to the university’s vast processing and storage capabilities is an important part of Wrubel’s lasting legacy, he said.
“Wrubel was a pioneer because he saw the promise of this technology for everyone across the university,” said Michael, who holds a Ph.D. in astronomy. “We don’t operate as a cost center, so we’re truly able to support science across all of IU, regardless of discipline.”
Counting the stars
Among the projects currently supported by IU’s high-performance computing resources are the Blanco DECam Bulge Survey. Pilachowski is a leader on this NSF-funded study, which seeks to map the “galactic bulge” through the collection and analysis of data on more than 75 million stars in the Milky Way.
IU astronomers are also collaborating with Research Technologies on an effort to simulate the evolution of star clusters. Led by Enrico Vesperini, associate professor of astronomy, this project involves modeling the behavior of millions of stars over time.
IU astronomy research also relies on the university’s massive digital storage capacity. The department uses UITS services to host the world’s largest database of precise information about galaxies, for example. The NASA-funded project, led by assistant professor of astronomy Samir Salim, contains information on over 700,000 galaxies. The resource has been used to inform hundreds of astronomy studies across the globe.
Telescopic ambitions
As the site of one of the country’s first robotic telescopes, IU has also been a pioneer in telescopy, Pilachowski said. Led by R. Kent Honeycutt, professor emeritus of astronomy, IU established a “RoboScope” in the Morgan Monroe State Forest in the late 1980s, which was primarily used to conduct fully automated observations of white dwarf star systems.
Most of IU’s astronomical data currently comes from the WIYN telescope at Kitt Peak National Observatory near Tucson, Arizona, Pilachowski added. As a founding member of the Wisconsin-Indiana-Yale-NOIRLab Consortium, IU’s Department of Astronomy has access to more than 50 nights of observing time on the telescope each year.
Research supported by this resource includes a study of star formation in galaxies across cosmic time, led by Provost Professor of Astronomy John Salzer; and a study to investigate the physical processes inside stars through the measurement of lithium, beryllium and boron and on their surfaces, led by professor of astronomy Constantine Deliyannis. Katherine Rhode, associate professor of astronomy, also uses the WIYN telescope’s excellent image quality to discover the faintest galaxies in and round the Local Group, a collection of galaxies that include the Milky Way
IU Asteroid Program
Indiana University played a role in another historically significant astronomical project, Pilachowski said. From 1949 to 1966, the IU Asteroid Program produced photographic plates of 12,000 asteroids, including many whose locations were lost during the global interruption of regular astronomical observations during World War II.
The program was also responsible for the discovery of 119 new asteroids, and many new minor planets in the Earth’s solar system. The program’s observations were carried out by a 10-inch astrograph — or a telescope designed for astral photography — on the site of the Link Observatory in Morgan County, which is now operated by the Indiana Astronomical Society.
The upcoming eclipse
For the 2024 solar eclipse, IU scientists are doing more than educating the public about the event; they are playing a key role in collecting important scientific observations during it.
The Department of Astronomy is one of only three regional coordinating sites for Citizen CATE. A NASA- and NSF-funded project, Citizen CATE aims to capture a nearly hourlong video of the sun’s corona during the eclipse, the super-hot outer edge of the sun’s atmosphere that is otherwise nearly impossible to observe due to the brightness of the sun.
“As the Midwest regional coordinator for the project, we’ll be helping contribute to the work of others who are studying properties of this part of the sun,” Pilachowski said. “We are right in the middle of it all.”