The Swedish Solar Telescope (SST), operated by the Institute for Solar Physics of the Royal Swedish Academy of Sciences, is the largest solar telescope in Europe and a world leader in high spatial resolution. Located at the Roque de los Muchachos Observatory in La Palma, it combines high-quality optics, adaptive optics, and advanced image reconstruction techniques to study solar structures with unprecedented detail.

With a 97 cm aperture, the SST has achieved a resolution of 0.1 arcseconds in blue light, equivalent to 70 km on the solar surface. This level of detail has allowed the discovery of previously unknown solar features, such as dark cores in the filaments of sunspot penumbrae and narrow, dark structures near sunspots, referred to as ‘hairs’ and ‘canals.’

The SST employs a unique optical design with a 1.07 m fused silica lens and an evacuated tube to prevent image degradation from heated air. Additionally, it features an adaptive optics system that corrects atmospheric distortions, enabling sharp images of the Sun. The scientific instrumentation is mounted on optical benches in a lab environment, facilitating adaptation to specific research needs.