ATLANTA — Georgia State University’s Center for High Angular Resolution Astronomy (CHARA) Array is marking a major new investment in the facility’s future as its global research community continues to expand.
The U.S. National Science Foundation (NSF) has awarded Georgia State a $915,343, three-year grant for a project titled “Resolving the Inner Winds of Massive Stars.” The project will advance fiber-optics technology at the CHARA Array, completing connections between telescopes and enabling longer baselines and higher angular resolution.
Located on Mount Wilson in California, the CHARA Array is one of the world’s premier facilities for high-resolution optical and infrared astronomy. The array operates by combining light from six fixed-position telescopes and one mobile telescope to achieve the angular resolution of a much larger telescope.
The new NSF-funded project will complete fiber-optic connections between telescopes, extending the array’s longest baselines — the distances between its telescopes — and allowing astronomers to see finer details in the sky. This increased resolution will open a new window onto the environments immediately surrounding massive stars.
“Fiber optics offer us a new way to combine the telescopes of the array. By connecting the mobile telescope at a southern location with the most extreme east- and west-position telescopes, we will almost double the vision power,” said Regents’ Professor of Astronomy and Director of CHARA Douglas Gies .
The research will focus on stellar winds — powerful outflows of gas that massive stars shed into space. These winds play a critical role in stellar evolution and can profoundly influence their surroundings and the kinds of neutron star and black hole remnants that massive stars create.
With improved angular resolution, researchers will be able to make more detailed observations of these outflows and compare them with increasingly sophisticated computer models of massive-star atmospheres and winds.
The scientific opportunity is especially significant as researchers move beyond one-dimensional descriptions of massive stars toward multidimensional models.
For example, simulations developed by Professor Jon Sundqvist’s group at KU Leuven’s Institute of Astronomy in Belgium predict intricate structures and instabilities in the winds of massive stars. New observations with CHARA’s array will provide an unprecedented opportunity to see the wind halos around massive stars and to test predictions about their properties.
This connection between theory and observation is central to CHARA’s role, allowing researchers across institutions and disciplines to refine models using direct, high-resolution measurements.
The NSF award comes as CHARA’s international scientific impact continues to grow. Since 2005, some 300 refereed publications featuring CHARA data have appeared in the scientific literature, accumulating 14,576 citations. The work represents contributions from 919 scientists at 361 institutions in 42 countries.
“These numbers illustrate something fundamental about CHARA,” said Gies. “It is not simply a Georgia State facility at Mount Wilson. It is an international scientific resource, bringing together researchers who are using high-angular-resolution observations to answer questions that cannot be addressed with conventional telescopes.”
Researchers and students from around the world participate in CHARA observing programs, collaborate with Georgia State astronomers and use data from the array to study stellar astrophysics and other phenomena that require exceptionally high-angular resolution.
The facility’s international reach is reflected in its publication record, with scientists from around the globe contributing to research based on CHARA observations. For these teams, the array provides access to spatial scales that are inaccessible to conventional telescopes. For Georgia State, the collaborations connect researchers and students with an international community at the forefront of observational astronomy.
The new NSF project strengthens that community while advancing the technology that supports its research.
The project also builds on Georgia State’s investment in innovative CHARA instrumentation. Development of mobile telescope technology previously received support from the university’s Provost’s Office as matching funds for an earlier NSF grant.
That work established a technological foundation for continued development at the array.
“The mobile telescope project demonstrated how investments in innovative instrumentation can expand what CHARA is capable of doing,” said Gail Schaefer , the CHARA Array's director in California. “This new NSF support allows us to take another significant step forward, particularly in the fiber-optics infrastructure needed to exploit the array’s longest baselines.”
For more information about CHARA, visit the website at charaarray.gsu.edu. For more information about Georgia State research and its impact, visit research.gsu.edu .