BlackGEM telescopes at La Silla Observatory in Chile officially opened

Minister Robbert Dijkgraaf of Education, Culture and Science officially opened the BlackGEM telescope array at ESO's La Silla observatory. BlackGEM consists of three optical telescopes that will be looking for flashes of light from merging black holes and neutron stars. BlackGEM was developed and built by a Dutch/Flemish consortium led by NOVA and Radboud University.

AlsWhen gravitational detectors such as Virgo, LIGO (and possibly the future Einstein Telescope) detect a gravitational wave, they designate a region in the sky the size of at least 20 by 20 full moons from which the signal originates. BlackGEM is designed to search very efficiently in this region immediately after detection for any optical phenomena that may accompany the gravitational wave, such as gamma-ray bursts. BlackGEM can then trace the exact spot where the collision occurred, following which larger telescopes can be pointed at the source to make follow-up measurements across the electromagnetic spectrum.

Robbert Dijkgraaf: “The fact that we can now use BlackGEM to locate the source of gravitational waves in the sky provides us with a wealth of information. This allows us to better understand some of the most mysterious phenomena in the universe, such as colliding neutron stars. What also makes this pioneering tool special is that it is a Flemish-Dutch initiative.”

Hunt for the source

Gravitational waves cannot be seen: they are ripples in spacetime created by collisions of black holes and neutron stars. Their extremely weak signal can be picked up with modern detectors. BlackGEM can then hunt for the source of the signal, following which larger telescopes can be used to make precise follow-up observations.

The opening of BlackGEM took place at the European La Silla observatory in the presence of many guests, including Minister Dijkgraaf, the Dutch ambassador to Chile, Director General of the European Southern Observatory (ESO) Xavier Barcons, and BlackGEM's project leader Paul Groot (NOVA/Radboud University).

Minister Dijkgraaf is currently visiting a number of observatories in Chile that are of great importance for Dutch astronomy. Dutch astronomers, engineers, and also companies are contributing to this scientific infrastructure. For example, TNO and VDL are building the support structure for the 39-metre main mirror of ESO's Extremely Large Telescope (ELT), now under construction on Cerro Armazones and due to go into operation later this decade. 

Very Large Telescope

The Netherlands Research School for Astronomy (NOVA) developed and co-built numerous instruments on ESO's Very Large Telescope on Cerro Paranal, is making contributions to several instruments on the ELT, and is in charge of one of the first-generation ELT instruments. For the sub-mm ALMA telescope, located 5000 metres above sea level on the Chajnantor plateau in the Andes, NOVA built the receivers for all 66 ALMA dishes to make observations at three different wavelength ranges.

The Netherlands is one of ESO's key partners in the development and construction of instruments for the large telescopes in Chile. As a result, astronomers affiliated with Dutch universities are also among the first to be allowed to make observations using the latest instruments, which has produced a wealth of scientific results for decades. Historically, the Netherlands has also played an important role in ESO's development. In the early 1950s, a group of Leiden astronomers were the first to discuss the possibility of creating a joint European observatory. In 1962, the Netherlands was a founding member of ESO. In total, four Dutch people have led ESO as director general since then.

Credit photo: NOVA/Thomas Wijnen

Contact information

For further information, please contact one of the researchers involved or team Science communication via +31 24 361 6000 or media [at] (media[at]ru[dot]nl).