The William Herschel Telescope, inaugurated in 1987, is one of the largest optical telescopes of its kind in Europe, with a primary mirror of diameter 4.2 metres.
Its state-of-the-art instrumentation together with the superb sky quality of the Roque de Los Muchachos Observatory have made the William Herschel Telescope one of the most scientifically productive telescopes in the world.
It is a general-purpose facility, instrumented to allow a wide range of astronomical observations, from the optical wavelengths to the infrared, and covering both imaging and spectroscopy. Through continued development of instrumentation, particularly in the field of adaptive optics, the William Herschel Telescope remains at the forefront of astronomical research.
The telescope played an important role in discovering the accelerated expansion of the Universe, and it has made important contributions in the fields of observational cosmology, gamma-ray bursts, galaxy dynamics and star evolution.
More information can be found at the ING Public Information web pages.