The European Solar Telescope (EST) is a next generation large-aperture solar telescope. With a 4.2-metre primary mirror, it will be optimised for studies of the magnetic coupling of the solar atmosphere. This will require diagnostics of the thermal, dynamic and magnetic properties of the plasma over many scale heights, by using multi-wavelength imaging, spectroscopy and spectropolarimetry. EST will specialise in high spatial and temporal resolution, using several instruments simultaneously to efficiently produce 2D spectral information. EST will be located in the Canary Islands, a first-class site for astronomical observations.
Why is EST needed?
A consensus exists among solar astronomers worldwide that a significant increase in observing capability is needed to understand the fundamental processes that control plasma physics in the Sun's outer atmosphere, approaching the following key questions as a priority goal
Study astrophysical processes
What can the Sun teach us about fundamental astrophysical processes, both in stars and other celestial objects? Observations of the Sun reveal intricate patterns of magnetic fields and the complex dynamics of a stellar atmosphere at their intrinsic spatial scales.
What drives solar variability on all scales? The Sun varies on a wide range of spatial and temporal scales, producing very energetic phenomena. We still do not fully understand these changes and cannot accurately predict basic aspects of solar variability.
Solar activity impact
What is the impact of solar activity on Earth? Solar magnetic activity can affect millions of people on short and long time scales. We need to predict disturbances of the space environment induced by the Sun and to understand the links between the solar output and the Earth's climate.
What is the European added value?
European solar physicists unanimously share the view that a new generation, large aperture solar telescope is needed to further understanding of the fundamental processes of plasma physics in the Sun's atmospheric layers. The construction of EST, equipped with adaptive optics and integral field spectropolarimeters for observing astrophysical processes at their intrinsic scales, will allow the interaction between magnetic fields and plasmas in the solar atmosphere to be studied in unprecendented detail.
Building EST will guarantee European solar astronomers access to an essential tool for ground-based solar research that will bring in scientific benefits not only in quantity but also in quality. EST will be the largest solar telescope ever built in Europe. It is a key element for developing not only the European solar research area but also the Canary Islands' astrophysical observatories. Moreover EST will give European industry, which is well prepared for this type of project, a unique opportunity to make returns from its expertise in the field.
The European Solar Telescope is a member of a coordinated effort to prepare ESFRI facilities and other pan-European infrastructures of astronomy, astroparticle, and particle physics for the European Open Science Cloud Initiative (EOSC).