Location: Observatorio del Teide, Spain
Owner: Centre National de la Recherche Scientifique (CNRS, France)
The Télescope Héliographique pour l'Etude du Magnétisme et des Instabilités Solaires (THÉMIS), owned by CNRS/INSU (France), is located at Observatorio del Teide in Tenerife, 2400 m above the sea level. With a 90 cm primary mirror, THÉMIS is currently the fourth largest solar telescope in the world. Its design allows for high-accuracy spectropolarimetry of the solar surface together with high-resolution monochromatic imaging. The telescope is filled with helium to improve image quality.