UC Santa Cruz will lead development of next-generation telescope alignment system

David Williams is a researcher in the Santa Cruz Institute for Particle Physics (SCIPP) and an adjunct professor of physics who has worked on the development of CTAO for nearly 20 years.

Amy Furniss is an associate teaching professor in the Physics Department.  (photo by Carolyn Lagattuta)

The National Science Foundation recently awarded $3.9 million to researchers at the University of California, Santa Cruz as the lead institution for the development of a next-gen telescope alignment system. The researchers will work with an international team to build and test systems in Santa Cruz and eventually install the final designs in seven telescopes at three ground-based observatory sites around the world. 

The alignment systems will be the first major United States contribution to the Cherenkov Telescope Array Observatory (CTAO), an international project that aims to improve our understanding of the universe through gamma-ray research.

“Very high-energy gamma rays give us a way to probe some of the most extreme events in the universe — things like gamma-ray bursts that come from the mergers of two black holes or the collapse of a star much more massive than our sun after it’s burned out,” said David Williams, a researcher in the Santa Cruz Institute for Particle Physics (SCIPP) and an adjunct professor of physics who has worked on the development of CTAO for nearly 20 years. 

Amy Furniss, a new UC Santa Cruz teaching professor, is working alongside Williams on the alignment system project. She added that studying extreme events helps scientists investigate the formation of the universe and the properties of matter.

“If you really want to understand how something works, you put it in extreme states,” she said. “So if you want to understand how steel works, you're going to heat it up and bend it around and do all these extreme things to it... the black holes, the galaxies, the pulsars, the gamma-ray bursts are doing the job of putting matter into those extreme states so we can really understand how it works.”

Dark matter is another focus for gamma-ray researchers, and the next generation of telescopes will open the door for new research questions.

“CTAO is uniquely capable of looking for those gamma rays from dark matter particles at a certain mass range that hasn’t yet been explored,” said Williams. 

The new CTAO telescopes are expected to be five to ten times more sensitive than the current generation of ground-based gamma-ray detectors. With over sixty telescopes at two sites — Paranal in Chile and La Palma in Spain — the CTAO will also allow scientists to complete sky surveys about three hundred times faster than is currently possible.

Researchers plan to install the first Medium-Sized Telescopes at the two CTAO sites. After their completion, CTAO intends to build at least 21 more Medium-Sized Telescopes, which could lead to additional involvement for UC Santa Cruz scientists and students. 

The Santa Cruz-led team will also install alignment systems at the Schwarzschild-Couder Telescope (SCT) prototype for CTAO at the Fred Lawrence Whipple Observatory in Arizona. The scientists expect that installation to begin in early 2026. 

The groundwork

Every telescope has around a hundred mirror segments that will each need their own alignment system. The lab at UC Santa Cruz will develop ideas for the systems, build prototypes and work with manufacturers to find a scalable option. In addition to being accurate, reliable and cost-effective, the systems must also be hardy.

“We need it to withstand the weather and the elements, because, unlike optical telescopes, the gamma-ray telescopes don't have domes over them. They're sitting out in the weather,” said Williams. 

The project is based out of the Santa Cruz Institute for Particle Physics, which “has long had a strength in doing instrumentation for high-energy particle physics and now high-energy particle astrophysics,” said Williams. Designing and testing the systems will allow early career scientists and students to experience hands-on research and training and contribute to a large international goal. 

“We’re going to be able to see things with higher resolution,” said Furniss. “We’re going to be able to see things farther afield, and our students, our graduate students and our faculty here at UC Santa Cruz, by putting in that work at the fundamental level, are going to be part of making this huge effort possible,” she said.

The Santa Cruz team will work with colleagues at UCLA, the Smithsonian Astrophysical Observatory (SAO), NASA Goddard Space Flight Center, and the Deutsches Elektronen-Synchrotron DESY and Institute for Astronomy and Astrophysics Tuebingen (IAAT) in Germany.  UCLA will lead the development of the positioning system for the SCT mirrors.  

SAO will manage the alignment system installation on the SCT and its subsequent operation.  The Goddard team will develop software for operating the SCT alignment system.  DESY is the lead group for the medium-sized telescopes at the two CTAO sites and will design and fabricate the electronics for the alignment systems on those telescopes.  

IAAT will provide precision test equipment and protocols to verify the performance of the production components for the CTAO sites.  Once completed, the project will also benefit other researchers around the country and the world.

“This is the first direct U.S. contribution to CTA construction,” said Williams. “And as such, it will potentially open up access to CTA data for U.S. scientists.”

As part of the grant, the researchers will also lead the development of K-12 curriculum about gamma-ray astronomy. Over the summer, experts in high-energy gamma-ray astrophysics will collaborate with educators to design materials for different grade levels. The following summer, researchers will host teacher trainings. 

“It’s an opportunity for us to create curricular materials and pedagogical tools so we can start introducing these different viewpoints of the universe from gamma rays into the classroom at the earliest stages possible,” said Furniss.

With the advances in technology led by UC Santa Cruz and CTA partners around the world, scientists expect there to be plenty of new, exciting observations to teach about in the years to come.

Artist’s rendering of the northern site of the Cherenkov Telescope Array Observatory, located in Spain. The telescope alignment system to be developed under the leadership of UC Santa Cruz will be used on the smaller of the two sizes of telescopes shown. (Credit: CTAO)