The next step in gravitational wave studies

A small step is being taken up the stairs to one of the BlackGEM telescopes in this Picture of the Week, but this facility represents a giant leap in gravitational wave studies at ESO’s La Silla Observatory in Chile. BlackGEM — which was developed by Radboud University, the Netherlands Research School for Astronomy, and the KU Leuven and officially inaugurated in January 2024 — is a mostly robotic array of optical telescopes designed to scan the southern sky. 

Each telescope in the array is aimed at different parts of the clear sky above La Silla, ever ready to detect the visible light afterglow of gravitational wave sources — cataclysmic events such as merging neutron stars or black holes. BlackGEM will pinpoint where these sources are and provide astronomers with a target for follow-up observations with other, larger telescopes to learn more about them. 

From the southern hemisphere, astronomers also have a pristine view of the Milky Way and our neighbour galaxies, the Magellanic Clouds, seen here in their characteristic wispy and cloud-like shape. In the Mapuche culture of south-central Chile, these clouds are known as lafken, labken or künchalabken (“the lagoons”) as well as rünanko (“the water wells”).