A team of researchers from Padua, Italy, has spent weeks refining a groundbreaking instrument intended to advance the study of the solar corona, the sun’s outer atmosphere. On August 12, as a total solar eclipse traverses Europe, the Circular Slit Spectrometer (CISS) will face its most significant challenge yet at Spain’s Javalambre Astrophysical Observatory. The team aims to demonstrate the device’s ability to analyze the Sun’s light across its constituent wavelengths with unprecedented speed.
The upcoming eclipse provides a rare opportunity to observe the corona, a region whose activity can significantly influence Earth’s power grids and communications infrastructure. Unlike traditional linear spectrometers that require hours to map the corona line by line—often missing rapid changes occurring over minutes—the CISS prototype offers a more efficient solution. Principal Investigator Federico Landini of the Astrophysical Observatory of Turin explained that the device features a circular slit, allowing it to capture the spectrum of the entire corona at a specific distance from the Sun’s center in a single image.
This project represents the culmination of two and a half years of intensive development. The team is now preparing for the fleeting window of totality, when the Moon obscures the Sun, to put their work to the ultimate test. Senior Researcher Paola Zuppella of the Institute for Photonics and Nanotechnologies noted that there is absolutely no room for error or unexpected issues during this brief period, emphasizing that precise team coordination and clear weather will be essential for success.
The researchers are taking significant precautions to ensure the instrument arrives safely in Spain. Rather than relying on air travel, which could be subject to last-minute cancellations, the team departed by road on Friday. By transporting the sensitive equipment in a van, they avoid the risks associated with dismantling and reassembling the device upon arrival. Landini stated that this overland journey was a necessary measure to guarantee their presence at the observatory.
If the mission proves successful, the new optical principle could be integrated into future space-based solar observation missions. This technology would serve as a successor to the UVCS, a major ultraviolet spectrometer that operated on the SOHO spacecraft between 1996 and 2013 but was limited by its slow mapping capabilities. By validating this prototype, the scientists hope to pave the way for more responsive and detailed solar monitoring in the future.
First, however, they must be ready for the brief window of totality, when the Moon blocks the sun, allowing scientists to observe the corona and putting 2-1/2 years of work to the test.