First Images from Inouye Solar Telescope Provide Detailed Look at Sun

The first images from the National Science Foundation’s (NSF) Inouye Solar Telescope show a close-up view of the sun’s surface, detailing a pattern of turbulent plasma that covers the entire sun. Cell-like plasma structures — each about the size of Texas — are the result of violent motions that transport heat from inside the sun to its surface. The telescope can image a region of the sun 38,000 km wide, and the images reveal the smallest features ever seen on the solar surface, some as small as 30 km.

Scientists will use the images from the telescope to map the magnetic fields within the sun’s corona, where solar eruptions occur that can impact Earth. “This telescope will improve our understanding of what drives space weather and ultimately help forecasters better predict solar storms,” NSF director France Córdova said.

Built by NSF's National Solar Observatory and managed by the Association of Universities for Research in Astronomy (AURA), the Inouye Solar Telescope combines a 13-foot mirror — the world’s largest for a solar telescope — with unparalleled viewing conditions at the 10,000-foot Haleakala summit. The telescope uses adaptive optics to compensate for blurring created by Earth’s atmosphere. The design of the optics (off-axis mirror placement) reduces scattered light for better viewing. Another, complementary optical system is used to precisely focus the telescope and eliminate distortions.

The Daniel K. Inouye Solar Telescope has produced the highest resolution image of the sun’s surface ever taken. In this picture, taken at 789 nm, scientists can see features as small as 30 km (18 miles) in size. The image shows a pattern of turbulent, “boiling” gas that covers the entire sun. The cell-like structures, each about the size of Texas, are the signature of violent motions that transport heat from the inside of the sun to its surface. Hot plasma rises in the bright centers of “cells,” cools off, and then sinks below the surface in dark lanes in a process known as convection. In these dark lanes the tiny, bright markers of magnetic fields can be seen. These bright specks are thought to channel energy up into the outer layers of the solar atmosphere, called the corona. These bright spots could be at the core of why the solar corona is more than a million degrees. Courtesy of NSO/AURA/NSF.

“With the largest aperture of any solar telescope, its unique design, and state-of-the-art instrumentation, the Inouye Solar Telescope — for the first time — will be able to perform the most challenging measurements of the sun,” Thomas Rimmele, director of the Inouye Solar Telescope, said. Scientists expect that, with data from the telescope, notification of potential impacts from space weather events could occur as much as 48 hours ahead of time instead of the current standard, which is about 48 minutes. This would allow for more time to secure power grids and critical infrastructure and to put satellites into safe mode.

The telescope will work with space-based solar observation tools such as NASA’s Parker Solar Probe (currently in orbit around the sun) and the European Space Agency/NASA Solar Orbiter (soon to be launched). Valentin Pillet, director of NSF’s National Solar Observatory, said that the telescope would provide remote sensing of the outer layers of the sun and the magnetic processes that occur in them. “These processes propagate into the solar system where the Parker Solar Probe and Solar Orbiter missions will measure their consequences,” Pillet said. “Altogether, they constitute a genuinely multi-messenger undertaking to understand how stars and their planets are magnetically connected.”

David Boboltz, program director in NSF’s division of astronomical sciences and overseer of the facility’s construction and operations, said that over the next six months, the team will continue testing and commissioning the telescope to make it ready for use by the international solar scientific community. “The Inouye Solar Telescope will collect more information about our sun during the first five years of its lifetime than all the solar data gathered since Galileo first pointed a telescope at the sun in 1612,” Boboltz said.

In this movie, taken at a wavelength of 705 nm over a period of 10 minutes, features as small as 30 km (18 miles) can be seen for the first time ever. The movie, which shows the turbulent, “boiling” gas that covers the entire sun, covers an area 36,500 × 36,500 km (22,600 × 22,600 miles, 51 × 51 arcseconds). Courtesy of NSO/AURA/NSF.