The operational phase begins for the CUBES (Cassegrain U-Band Efficient Spectrograph) project, an innovative ultraviolet spectrograph to be installed on the European Southern Observatory's Very Large Telescope (ESO's VLT) at the Paranal Observatory in Chile.

The CUBES project is carried out by a consortium of institutes from five countries, led by INAF together with Brazil, Germany, Great Britain and Poland.

On 15 February 2022, INAF President Marco Tavani and ESO Director General Xavier Barcons signed the CUBES Construction Agreement. After a preparatory study phase that lasted about a year (the so-called phase A), the operational phase (also called phase B) finally begins, involving the development of the instrument design, its construction and installation at the VLT.

“This is the first time that an instrument for the Very Large Telescope has been designed by an Italian-led consortium”, comments Marco Tavani, President of INAF. "This important stage testifies to the leadership role of the Italian astronomical community on the international scientific arena."

Modern telescopes are machines of remarkable complexity that require equally advanced instruments to be used at their best. The design and construction of new astronomical instruments represents a primary effort for the scientific community which sees in this an ambitious synthesis between scientific objectives and engineering opportunities.

As evidence of this continuous effort, the most advanced telescopes in the world, such as the VLT, experience the development of several generations of instruments throughout their "life". In this context, the CUBES project is an innovative tool dedicated to observing the sky in the ultraviolet portion of the electromagnetic spectrum, between 300 and 400 nanometers.

Astronomers observe the cosmos using a variety of technologies, from Earth and space, across the electromagnetic spectrum as well as through gravitational waves and the detection of neutrinos.

"The ultraviolet band is strongly absorbed by our atmosphere", adds Stefano Cristiani, principal investigator (PI) of CUBES, "but it contains unparalleled information on chemical elements, such as beryllium, that are key to understanding the evolution of stars, the explosion of massive objects, including the optical counterparts of gravitational wave sources and also basic aspects of cosmology and fundamental physics".

Building an efficient tool in such a complex observational band requires “a very complex design and optimization effort”, concludes Roberto Cirami, CUBES project manager.