French Involvement with the European Southern Observatory

This image shows the disc around the young AB Aurigae star, where ESO’s Very Large Telescope (VLT) has spotted signs of planet birth. The image was obtained with the VLT’s SPHERE instrument in polarised light, by a team led by French researchers. Credit: ESO/Boccaletti et al.

France is a founding member of ESO. The country signed the original convention on 5 October 1962 and officially became a Member State on 17 January 1964. As a founder, the country’s community of scientists and engineers has contributed to ESO projects in many key ways, from participating in scientific discoveries to contributing to the development of advanced instruments and telescopes for ESO facilities. 

France currently contributes 14.96% of ESO’s revenue (2021 contribution), worth 28 728 000 EUR. 

As of mid 2022, there are 76 French nationals employed at ESO, 55 in Germany and 21 in Chile. Furthermore, ESO has awarded 33 studentships, 66 fellowships and 13 internships to French nationals since 2004. 

France is represented in the various ESO governing and advisory bodies by astronomers and policy experts; the current French representatives of ESO’s various committees with national representation can be found here. 

The ESO Science Outreach Network (ESON) includes French representatives who act as ESO’s media and outreach local contacts. 

Here follows some information about France’s involvement with ESO. 

Discoveries by France-based astronomers using ESO telescopes 

French researchers and those based at French institutions have been involved in important discoveries using ESO facilities, including many of the ESO top 10 discoveries. More recent scientific discoveries include  

• The discovery of the largest group of rogue planets in a study led by Núria Miret-Roig (then at the Laboratoire d’Astrophysique de Bordeaux, France). Using a combination of several ESO facilities, they could observe the heat emitted by the planets. “There could be several billions of these free-floating giant planets roaming freely in the Milky Way without a host star,” explains Hervé Bouy (Laboratoire d’Astrophysique de Bordeaux), co-author of the study, in the ESO press release. 
• The discovery of the closest supermassive black hole pair by a team led by Karina Voggel (Strasbourg Observatory) using the MUSE instrument on ESO’s Very Large Telescope (VLT). The black holes were found in the NGC 7727 galaxy. 
• The imaging of 42 of the largest objects in the asteroid belt from a team led by French and Czech astronomers using the SPHERE instrument on ESO’s Very Large Telescope (VLT). Never before had such a large group of asteroids been imaged so sharply, revealing a wide range of peculiar shapes, helping astronomers trace the origins of the asteroids in our Solar System.  
• The first clear detection of a moon-forming disc around an exoplanet by Myriam Benisty (University of Grenoble and University of Chile) who led a team of researchers using ALMA. This discovery helps astronomers to better understand the origin of planets and moons.  

French involvement in ESO instruments and telescopes at ESO sites 

France has made and continues to make substantial contributions to many aspects of ESO, with French institutions behind many instruments based at telescopes on ESO sites. France is also behind some of the telescopes hosted at ESO sites. A few prominent examples of French involvement include 

• The planet hunter ExTrA (Exoplanets in Transits and their Atmospheres), a French national telescope at ESO’s La Silla Observatory. ExTrA, which saw first light in 2018, is designed to search for planets around nearby red dwarf stars and study their properties. The project, which consists of three 60-cm telescopes, is currently jointly funded by the European Research Council and the French Agence National de la Recherche. Its lead researcher is Xavier Bonfils (Institut of Planetology and Astrophysics of Grenoble, CNRS/UGA).
• Numerous instruments for ESO’s VLT Interferometer in which French institutions worked on, including AMBER, PIONIER, MATISSE, and GRAVITY.
• Several instruments on ESO’s VLT, which have had important contributions from French institutions. For example, CEA/DSM/DAPNIA (Saclay) led the development of VISIR, while the Laboratoire d'Astrophysique de Marseille (Observatoire Marseille-Provence), the Laboratoire d'Astrophysique de Toulouse (Observatoire Midi-Pyrénées) and the Observatoire de Haute-Provence were part of the VIMOS consortium. Many other VLT instruments, including SPHERE, NACO and MUSE were also developed through consortia led by French institutions.
• Through the University of Grenoble, France is part of the consortium behind ESO’s recently installed planet hunter: NIRPS. The instrument sits at ESO’s 3.6-metre telescope at La Silla Observatory and will characterise low-mass exoplanets, including rocky planets in the habitable zone. NIRPS will complement HARPS, which was developed by a French-Swiss consortium.
• The ALMA Band 7 receivers that were developed by the Institut de Radioastronomie Millimétrique (IRAM).
• France will become a member of the future CTA ERIC, the European Research Infrastructure Consortium, that will construct and operate the Cherenkov Telescope Array (CTA). The CTA will be a ground-based observatory for very high energy gamma-ray astronomy. It will consist of two arrays of dishes, a southern-hemisphere array hosted at ESO’s Paranal Observatory and a northern array on the island of La Palma, Spain. ESO will also be a member of the CTA ERIC and is represented in the council of the CTA. 

French involvement in ELT instruments 

French institutions are part of the consortia for all of the first six instruments that will be installed on ESO’s upcoming Extremely Large Telescope (ELT): 

• The MOSAIC instrument will peer closer at distant galaxies at the very edge of the observable Universe. It is being designed and built under the leadership of the National Institute for Earth Sciences and Astronomy at the National Centre for Scientific Research (CNRS-INSU, France) by a consortium of partners in France and other countries. 
• Five French institutions are part of the consortium behind ANDES (previously known as HIRES), the instrument that will study astronomical objects with unprecedented sensitivity. 
• The development of METIS, the Mid-infrared ELT Imager and Spectrograph is done by a consortium of many European countries, including France through the CEA Paris Saclay Research Centre. 
• MORFEO (previously known as MAORY) will enable other ELT instruments to take exceptional images of the Universe. France participates through the Grenoble Institute for Planetary Sciences and Astrophysics. 
• The MICADO instrument will take high-resolution images at near-infrared wavelengths, identifying exoplanets, resolving individual stars in other galaxies and investigating the mysterious centre of the Milky Way. A number of French institutes are part of the consortium.
• The HARMONI instrument is developed by a collaboration between France, Spain and the United Kingdom. HARMONI will have a sensitivity that is up to hundreds of times better than any current instrument of its kind. 

French industry and technology contributions to ESO 

As one of the founding ESO Member States and a country with one of the more significant contributions to the ESO budget, French institutions and industry have been awarded several important ESO contracts over the years. Some of France’s most significant technological contributions to ESO projects include 

• The Paranal instrumentation adaptive optics systems which were developed and produced by French company ONERA. 
• Winlight System SA which produced cameras for the ESPRESSO instrument 
• French company ALPAO which supplied all the deformable mirrors to equip the auxiliary telescopes that form part of ESO’s VLT Interferometer. 
• The Observatoire de Bordeaux which was awarded multiple contracts to produce the digitizer and tunable filter bank card production for ALMA. 
• Alcatel Space Industries which developed prototype antennas for ALMA, while the AEM Consortium developed the European ALMA antennas. 

French industry contributions to the ELT 

French companies have been key industrial partners of ESO’s Extremely Large Telescope. A few of the most significant contracts awarded to French industry include 

• Safran Reosc SAS which was awarded multiple contracts related to the ELT M1 segments polishing, ELT M2, M3 and M5 mirrors and auxiliary equipment, and the ELT M4 mirror shells. 
• SAGEM SA which was awarded multiple contracts related to the procurement of ELT primary mirror segment prototypes. 
• CILAS S.A. - Compagnie which conducted the design study for ELT M4 adaptive unit.
• FIRST LIGHT IMAGING S.A.S. which provided the C-RED One Cameras for the ELT.