The European Solar Telescope (EST) will be a revolutionary Research Infrastructure that will play a major role in answering key questions in modern Solar Physics. This 4-meter class solar telescope, to be located in the Canary Islands, will provide solar physicists with the most advanced state-of-the-art observing tools to transform our understanding of the complex phenomena that drive the solar magnetic activity. The principal objective of the present Preparatory Phase is to provide both the EST international consortium and the funding agencies with a detailed plan regarding the implementation of EST. The specific objectives of the proposed preparatory phase are: (1) to explore possible legal frameworks and related governance schemes that can be used by agencies to jointly establish, construct and operate EST as a new research infrastructure, with the implementation of an intermediate temporary organisational structure, as a previous step for future phases of the project; (2) to explore funding schemes and funding sources for EST, including a proposal of financial models to make possible the combination of direct financial and in-kind contributions towards the construction and operation of EST; (3) to compare the two possible sites for EST in the Canary Islands Astronomical Observatories and prepare final site agreements; (4) to engage funding agencies and policy makers for a long-term commitment which guarantees the construction and operation phases of the Telescope; (5) to involve industry in the design of EST key elements to the required level of definition and validation for their final production; (6) to enhance and intensify outreach activities and strategic links with national agencies and the user communities of EST. To accomplish the aforementioned goals, this 4-year project, promoted by the European Association for Solar Telescopes (EAST) and the PRE-EST consortium, encompassing 23 research institutions from 16 countries, will set up the Project Office

The SOLER project will investigate energetic solar eruptions starting from three perspectives: fast coronal mass ejections (CMEs), strong X-ray flares, and large solar energetic particle (SEP) events. Key parameters of the eruptions will be determined and their interrelations examined to improve our understanding on how the eruptive phenomena are linked, how they interact with each other, and how they result in acceleration of high energy particles and their release from the solar corona into interplanetary space. Large-amplitude coronal waves and shocks related to these events as well as magnetic connections of the radiation sources with the in-situ observers will be in focus as well. SOLER will answer three science questions: – What are the magnetic connections between EM radiation sources in the low corona and in the high corona and how are they connected to the particle radiation observed in situ? – What is the relation of the properties of the in-situ SEP observations with the source characteristics and between the source characteristics themselves? – What are the reasons for the large variations in SEP properties and associated flare and CME characteristics? Related to these scientific questions, SOLER has also technical objectives. SOLER will: – deliver interlinked catalogues of strong flares, fast CMEs and large SEP events. – deliver new tools for analysing and visualising solar eruption datasets and modelling results and distribute them openly to the scientific community. – produce several high-level multi-instrument datasets and distribute them openly to the scientific community. SOLER will use ESA, NASA and national mission data along with ground-based observations, and a variety of innovative data and image processing techniques together with cutting-edge models. SOLER analysis activities will directly lead to dozens of scientific publications. Catalogues, datasets and tools will be openly available for the community for further exploitation of data.