The solar corona, the outermost part of the Sun, is only visible with the naked eye during a total solar eclipse. Due to this, astronomers through the decades have had to get creative to study it. The latest invention is a suborbital telescope that was carried into space on a rocket for a flight time of a mere 10 minutes. In that brief amount of time, it managed to capture the highest resolution images yet of the solar corona. The findings are reported in The Astrophysical Journal.
The telescope, called the High-Resolution Coronal Imager (Hi-C), has the ability to see details as small as 70 kilometers (43 miles) in size. The team focused on the magnetized strands of plasma that populate the corona. The telescope imaged strands as “thin” as around 200 kilometers (125 miles) wide, although typical widths were more around 510 kilometers (320 miles).
“Until now solar astronomers have effectively been viewing our closest star in ‘standard definition’, whereas the exceptional quality of the data provided by the Hi-C telescope allows us to survey a patch of the Sun in ‘ultra-high definition’ for the first time,” Robert Walsh, institutional lead for the Hi-C team and professor from the University of Central Lancashire, said in a statement.
This was the third launch of Hi-C, with more planned for the future. The team will also overlap their observations with NASA’s Parker Solar Probe and ESA’s Solar Orbiter (SolO). The former is already studying the Sun and the latter was launched in February.
“These new Hi-C images give us a remarkable insight into the Sun’s atmosphere. Along with ongoing missions such as Probe and SolO, this fleet of space-based instruments in the near future will reveal the Sun’s dynamic outer layer in a completely new light,” Dr Amy Winebarger, Hi-C principal investigator at NASA MSFC, explained.
Scientists have yet to fully understand how the corona became so hot. The corona has a temperature of millions of degrees, which is puzzling given that the surface of the Sun is around 5,500°C (about 10,000°F). Hi-C and the other solar missions hope they will gather enough data to solve this mystery once and for all.