Earlier this month a contract was signed to fund the conceptual study of a new telescope, the Wide Field Spectroscopic Telescope (WST), which could potentially become operational in Chile after 2040.
The international consortium will propose WST as a candidate to become the next major observatory infrastructure project for the European Southern Observatory (ESO) after the completion of the Extremely Large Telescope (ELT).
The innovative WST project aims to build a telescope entirely dedicated to wide-field spectroscopic surveys in the optical band, covering all types of celestial objects—from distant galaxies to asteroids and comets within our Solar System. The project was selected as part of the European Union's Horizon Europe Framework Program under a competitive call for research infrastructures. The international consortium leading the WST project received €3 million to be used over 2025-2027 to complete a detailed conceptual study of the new telescope.
The consortium is made up of 19 research institutions (including UK ATC) across Europe and Australia, with a science team of over 600 members from 32 countries distributed in all five continents. The project is led by Roland Bacon of Centre National de la Recherche Scientifique (CNRS, France) and Sofia Randich of Istituto Nazionale di Astrofisica (INAF, Italy).
WST promises to fulfill a critical need identified by the international scientific community: a telescope with a 10-meter class primary mirror exclusively dedicated to the spectroscopic observations of celestial sources. The demand for such an observational infrastructure is explicitly stated in numerous strategic international scientific plans outlining the key priorities for astrophysical research in the coming decade, including the European Astronet Roadmap 2023.
Sofia Randich of INAF said: “The Wide Field Spectroscopic Telescope will produce cutting-edge, transformative science and will allow researchers to tackle key scientific questions in areas such as cosmology; the formation, evolution, and chemical enrichment of galaxies (including the Milky Way); the origin of stars and planets; astrophysics of transient or time-variable events; and multi-messenger astrophysics."
The concept study funded by Horizon Europe will address all relevant aspects needed to form a comprehensive picture: the telescope design and instruments, the selection of the site in Chile where the telescope will be located, further development of scientific cases, the preparation of a survey plan, as well as an operational model for the facility and plans for innovative data reduction and analysis, with the goal of maximizing scientific return.
The UK ATC participates in a wide range of activities, from science definition to leading the development of the instrumentation suite and calibration unit, defining the operational model for the facility, and contributing to the design of the positioners.
The study will pay particular attention to environmental sustainability. Environmental impact will be one of the criteria guiding technological choices and trade-offs, and solutions will be developed to mitigate major sources of carbon dioxide emissions. The projected environmental impact for both the construction and operational phases of WST will be documented in detail at the end of the study.
In the near future, ESO will open a call for ideas to evaluate projects for investment after ELT is completed. If approved, WST would become the next major ESO facility, with the potential to address groundbreaking astrophysical questions in the 2040s.
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