The Indian Space Research Organisation (ISRO) has released visuals showcasing the shutter operation of the Solar Ultraviolet Imaging Telescope (SUIT) instrument aboard Aditya L1. This instrument has recently achieved success in capturing the first full-disk images of the Sun in the 200-400 nm wavelength range.

The video, captured on December 5 by onboard camera, shows the opening and closing of the SUIT probe's aperture, facilitating the entry of solar radiation into the payload and to the thermal filters.

“If all of the radiation from the Sun is allowed to enter the optical cavity, the mirrors and the detector would get damaged due to overheating,” said Manish Purohit, former ISRO scientist.

To prevent this, Purohit added, a metal-dielectric thermal filter is employed, reflecting the majority of solar flux below 200 nm and above 400 nm. Only 1 per cent of the flux in this range is transmitted to SUIT's main optical chamber, he added.

Purohit detailed the use of two filter wheels with distinct filters to balance fluxes at the detector across frequency bands.

“There are two filter wheels with different filters to balance the fluxes at the detector in different frequency bands. The two filter wheels can be driven independently to achieve the desired combination. The shutter mechanism is used to control the exposure with different filter combinations to achieve the desired signal-to-noise ratio,” he explained.

The SUIT probe on Aditya-L1 provided scientists with insights into sunspots and various regions on the Sun, aiding in the study of its outer layers—the photosphere and chromosphere. These observations are crucial for understanding the interconnection of the Sun's magnetic atmosphere and the impact of solar radiation on Earth's climate.

Launched on September 2 by the ISRO, Aditya L1 is India's inaugural space mission to study the Sun. To be positioned in a halo orbit around Lagrange point 1 (L1) of the Sun-Earth system, approximately 15 lakh km from Earth, the spacecraft boasts a unique advantage of continuously observing the Sun without interruptions.

This unobstructed view enables real-time monitoring of solar activities and their impact on space weather, marking a significant stride in solar research.