European scientists are taking advantage of this week’s solar eclipse to test a potentially groundbreaking instrument that could transform the way astronomers study the Sun.
For weeks, a team from the Astrophysical Observatory of Turin has been stationed at Spain’s Javalambre Astrophysical Observatory, preparing to deploy a novel spectrometer ahead of the August 12 eclipse.
On that date, researchers will activate the Circular Slit Spectrometer (CISS), which the Turin-based team says will provide a unique new view of our life-giving star. Specifically, the device will focus on the corona, the outermost portions of the Solar atmosphere, and the hottest part of the Sun.
The 2026 Solar Eclipse: A Trio of Occurrences
This month, skywatchers will be treated to a trio of celestial events: a solar eclipse and the peak of the Perseids meteor shower on August 12, followed by a lunar eclipse between August 27 and 28. The total solar eclipse will be best viewed from parts of Spain, Portugal, Russia, Iceland, and Greenland, while observers across much of Europe, Africa, and North America will experience only a partial eclipse.
To take advantage of the event, the research team traveled from its home base in Padua, northern Italy, to Spain, where years of development work will culminate in the first field test of CISS. The scientists believe the new instrument could significantly improve observations of the Sun’s corona.
Opportunities Arise During the European Eclipse
Spectrometers are among astronomers’ most valuable tools, allowing researchers to analyze the composition of stars and even detect the atmospheres of distant exoplanets by examining subtle changes in starlight.
Closer to home, the Italian team believes CISS can separate the wavelengths of sunlight far more rapidly than existing instruments. That capability could prove especially valuable because the corona drives powerful space weather events capable of disrupting communications, power grids, and GPS systems on Earth and in orbit.
The researchers see the eclipse as the ideal opportunity to test their instrument, since the Moon’s passage in front of the Sun dramatically increases the contrast of the corona against the sky. For the team, the observation marks the culmination of more than two and a half years spent rethinking some of the fundamental design principles behind conventional spectrometers.
CISS: A Spectrometer Unlike Any Other
Unlike traditional spectrometers, which typically rely on a narrow rectangular slit, CISS uses a circular slit. This allows it to “capture the spectrum of the entire corona at a certain distance from the centre of the Sun in a single photograph,” according to principal investigator Federico Landini of the Astrophysical Observatory of Turin.
By redesigning the instrument’s aperture, the researchers say they have reduced the time needed to scan the corona from hours to just minutes. If successful, the eclipse demonstration could pave the way for incorporating the technology into future space missions designed to observe the Sun from closer vantage points.
For now, the team is focused on ensuring the best possible observing conditions. Researchers continue to monitor the weather, with current forecasts appearing favorable for eclipse viewing. To minimize the risk of equipment problems, the team transported CISS from Italy to Spain by van rather than by air, avoiding the need to disassemble the instrument and reducing the possibility of flight delays or cancellations.
Later this week, they will learn whether years of work have produced a breakthrough in solar observation—or simply the next step in refining a promising new technology.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org.