Building the world’s largest telescope

The ELT dome under construction in Chile Credit: ESO/G. Vecchia
The ELT dome under construction in Chile Credit: ESO/G. Vecchia

In 2014, the European Southern Observatory (ESO) began construction of the world’s largest telescope, the Extremely Large Telescope (ELT), at an altitude of over 3,000 m in Chile’s Atacama Desert. Scheduled to enter service in 2028, this giant telescope promises to mark a new era in ground-based astronomy. A Canadian team will be involved in the design and manufacture of the ANDES spectrograph, which will search for signs of life outside the solar system.

On June 5, ESO signed an agreement with a consortium of organizations from 13 countries for the design and manufacture of the ANDES spectrograph (for ArmazoNes high Dispersion Echelle Spectrograph). The instrument, which will be installed on this telescope, will be used to search for signs of life on exoplanets and the very first stars, as well as to test variations in the fundamental constants of physics and measure the acceleration of the expansion of the Universe.

A Canadian team, represented by the Université de Montréal and co-directed by Professor René Doyon , is one of the main contributors to this innovative near-infrared spectrograph project.

What is a spectrograph?

A spectrograph is an instrument that breaks light down into its various wavelengths, so that astronomers can determine important properties of celestial objects, such as their chemical composition.

The ANDES instrument will be particularly powerful, with record-breaking accuracy in the visible and near-infrared wavelengths. Combined with the ELT’s efficient mirror system, it will pave the way for research in a wide range of astronomical fields.

It will therefore be able to carry out detailed surveys of the atmospheres of Earth-like exoplanets, enabling astronomers to search for signs of life on a large scale.

It will also be able to analyze the chemical elements present in distant objects in the young Universe, making it probably the first instrument capable of detecting the signatures of population III stars, the first stars born in the Universe.

In addition, astronomers will be able to use ANDES data to check whether the fundamental constants of physics vary with time and space. Its comprehensive data will also be used to directly measure the acceleration of the expansion of the Universe, one of the most enduring mysteries of the cosmos.

Canadian participation in the search for life in the Universe

The Canadian team is led by the Observatoire du Mont-Mégantic and its experimental astrophysics laboratory, under the leadership of René Doyon, the team’s co-principal investigator and Professor of Astrophysics at UdeM.

The project also includes design work by the National Research Council’s Herzberg Research Centre for Astronomy and Astrophysics, which is working closely with the Canadian ANDES science team, co-directed by Kim Venn of the University of Victoria, the project’s other co-principal investigator.

The Canadian team is developing the near-infrared spectrograph, adaptive optics, control systems and data reduction, as well as providing highly qualified scientific personnel.

The ambitious goals of ANDES, such as detecting the signatures of life in the atmospheres of exoplanets and studying the first stars of the Universe, are perfectly in line with the cutting-edge research being carried out by Canadian scientists, in particular at UdeM’s Institut Trottier de recherche sur les exoplanètes, the largest exoplanet research center in Canada.

This collaboration highlights Canada’s strong capabilities in infrared astronomy, and underscores the country’s leadership in astrophysical research and its commitment to advancing our understanding of the Universe.

ANDES will have a significant impact on all branches of astrophysics, thanks to its unique ability to detect the spectral signatures of life in the atmosphere of potentially habitable exoplanets close to the Sun," explains René Doyon. It will also encourage the Canadian astronomical community to use the ELT, which should be operational in a few years’ time."

Canadian participation was made possible thanks to the extensive infrared expertise acquired by the Laboratoire d’astrophysique expérimentale at the Mont-Mégantic Observatory: "This participation enables Canadian scientists to contribute to the design and construction of an instrument for the world’s largest telescope, giving Canadian astronomers valuable observing time to further our understanding of the Universe," adds astrophysicist Frédérique Baron, project manager of the Canadian instrument team at UdeM.