Dutch Involvement with the European Southern Observatory 

The active galaxy Messier 77 with a thick ring hiding a supermassive black hole. (Credit: ESO/Jaffe, Gámez-Rosas et al.)

The Netherlands is one of the five founding members of ESO who took part in signing the ESO convention on 5 October 1962. It officially became a Member State on 17 January 1964. As a founding member, the Dutch 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 instruments and telescopes. 

The Netherlands contributes 5.01% of ESO’s revenue (2021 contribution), worth 9 621 000 EUR. 

As of mid 2022, there are 14 Dutch nationals employed at ESO, 11 in Germany and three in Chile. Furthermore, ESO has awarded 12 studentships and seven fellowships to Dutch nationals since 2004. 

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

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

Here follows some information about Dutch involvement with ESO. 

Discoveries by astronomers based in The Netherlands using ESO telescopes 

Dutch researchers and those based at Dutch institutions have been involved in important discoveries using ESO facilities. These include 

• Master's student Nashanty Brunken at Leiden Observatory, who together with other Leiden researchers, discovered the largest molecule ever found in a planet-forming disc using ALMA. The molecule, dimethyl ether, is believed to be a precursor of larger organic molecules that can lead to the emergence of life.
• A team of astronomers led by Violeta Gámez Rosas from Leiden University who used the MATISSE instrument on ESO’s Very Large Telescope Interferometer (VLTI) to observe a ring of cosmic dust and gas hiding a supermassive black hole in the galaxy Messier 77. This discovery provided vital evidence to support a 30-year-old theory known as the Unified Model of Active Galactic Nuclei. 
• The first ever direct imaging of a multi-planet system around a Sun-like star which was observed using the SPHERE instrument on ESO’s Very Large Telescope (VLT). The discovery, made by Alexander Bohn at Leiden Observatory with collaborators, can help give new insight into how our own solar system formed.
• In 2018, when ESO’s VLT captured details of an elaborate serpentine system of three stars, sculpted by colliding stellar winds. “This is the first such system to be discovered in our own galaxy,” explained Joseph Callingham of the Netherlands Institute for Radio Astronomy (ASTRON), lead author of the study reporting this system, in the ESO press release on the discovery. “We never expected to find such a system in our own backyard”. 

Dutch involvement in ESO instruments and telescopes at ESO sites 

The Netherlands has contributed to many aspects of ESO, including the technology behind instruments, ESO telescopes and telescopes based at ESO sites. These include 

• MASCARA (the Multi-site All-Sky CAmeRA), built and operated by Leiden University, which is a planet-hunting instrument that consists of two individual stations, one operating in each hemisphere. One of the stations lies in the south and takes advantage of the excellent observing conditions at ESO’s La Silla Observatory in Chile. 
• The OmegaCAM, which is mounted on the VLT Survey Telescope (VST) at ESO’s Paranal Observatory and is made up of 32 individual CCD cameras arranged in a mosaic. The camera is a specialist at mapping the sky quickly and with very fine image quality. It was built by a large consortium consisting of institutes based in Germany, Italy, ESO and led by the Netherlands (NOVA, Kapteyn Instituut, and OmegaCEN). 
• BlackGEM, which is a wide-field array of optical telescopes that will observe gravitational wave sources. It comprises 3 telescopes, with the aim to expand to 15. BlackGEM is jointly developed by Radboud University, the Netherlands Research School for Astronomy (NOVA), and the KU Leuven. The array is located at La Silla, and is largely robotic and remotely controlled from Radboud University. 
• The upcoming 4MOST spectrograph for the VISTA telescope at Paranal Observatory which is being developed by a consortium in which the Netherlands are involved through NOVA (The Netherlands Research School, represented by Leiden Observatory and the Netherlands Institute for Radio Astronomy, ASTRON) and the University of Groningen.  
• Several VLT instruments, which were developed by consortia with Dutch members. These include MUSE (Leiden Observatory), SINFONI (NOVA, ASTRON), SPHERE (Astronomical Institute of Amsterdam, NOVA, ASTRON) and X-shooter (University of Amsterdam, ASTRON).
• Through the Netherlands Institute for Space Research (SRON), the Netherlands has contributed to many instruments for the APEX telescope, such as CHAMP and FLASH.
• The Dutch 0.9-metre telescope, which was installed at La Silla between 1979 and 2006, and contributed towards several different discoveries. 
• The development of several of ALMA receivers, for ALMA’s Band 2, 5 and 9, which the Netherlands contributed to through NOVA. 

Dutch involvement in ELT instruments 

• The development of METIS, the Mid-infrared ELT Imager and Spectrograph, on ESO’s upcoming Extremely Large Telescope (ELT), is led by NOVA in the Netherlands. The powerful spectrograph will allow studies of a wide range of astrophysical phenomena, from exoplanet atmospheres to distant and active galaxies.
• The Netherlands, through NOVA, is also involved with the development of the ELT’s MICADO and MOSAIC instruments. 

Dutch industry and technology contributions to ESO 

The Netherlands has contributed to many aspects of ESO, with many contracts awarded to the Dutch industry, including to 

• TNO, the Netherlands Organisation for applied scientific research, which developed and built the optical tube assemblies for the Four Laser Guide Star Facility (4LSGF) on the VLT, key for getting crystal clear observations.  
• Coherent Europe B.V., which was awarded a contract for VLT laser maintenance 

Dutch industry contributions to the ELT 

• The contract to design and produce the qualification models for the segment support and related auxiliary equipment for the ELT primary mirror (M1) have been contracted to the Dutch VDL Groep. The same company is also in charge of the design, production and testing of the mirror segment supports for M1. 
• TNO was awarded contracts for the ELT laser beam projection units and the M1 prototype segments subunits.