Thanks to a newly expanded app, even more amateur astronomers can now take part in the hunt for black holes.
Black Hole Finder is the brainchild of the Dutch Black Hole Consortium, a group of more than 30 scientists and researchers who, as their name suggests, explore the mysterious regions of space from the Netherlands. Part of their research is based on images taken by the BlackGEM telescopes in the Chilean Atacama Desert, which are dedicated to studying dramatic cosmic events and objects such as black holes or merging neutron stars.
Such events create ripples in space-time called gravitational waves. If they occur within 650 million light-years, they can be detected by ground-based telescopes on Earth. In fact, despite the enormous distance, these waves can still be detected by instruments like MIT’s Laser Interferometer Gravitational-Wave Observatory (LIGO), although they may be faint. When these waves are detected, the telescopes, controlled by the Netherlands’ Radboud University, search the southern sky for their source. That’s where citizen scientists – and the newly updated app – come in.
When users open the app, they are shown images taken by the BlackGEM telescopes just 15 minutes after they were taken. They are then tasked with looking for potential kilonovas – brief bursts of light caused by the merging of neutron stars. These collisions lead to a star collapsing and forming a black hole.
However, not all of the flashes of light observed by the telescopes are kilonovas. Some could be satellites orbiting the Earth or just a glitch. Black Hole Finder users are asked to rate the photos to determine whether a photo shows an actual kilonova or a false positive. The data is then used to train a machine learning system that can better identify the birth of black holes.
Users’ task is to closely examine the shape of flashes of light and compare photos of the same area of space taken at different times. The app provides detailed instructions so that even a layperson can contribute to the search.
“An immediate warning goes out to astronomers, who quickly aim their telescopes to search for the newly formed black hole,” explains the Dutch Black Hole Consortium on its website. “After a neutron star collision, rare elements such as iodine, gold and cerium are produced in a kilonova explosion. Such a kilonova is accompanied by a weak, short-lived light signal that telescopes can detect if they are quickly pointed at the source.”
To make things even more interesting, the Black Hole Consortium has gamified the black hole hunt. Citizen scientists can monitor their statistics and climb the ranks to reach new status levels. At certain levels, they receive new privileges or rewards, such as the ability to request follow-up information on the transients they identify.
Launched in November 2023, the app was originally only available in English and Dutch. In an update on August 13, the app was expanded to include Spanish, German, Chinese, Bengali, Polish and Italian versions. Black Hole Finder is available on Google Play, the App Store and as a web app.
If the idea of making a major astronomical discovery as an amateur sounds far-fetched, rest assured: It’s happened before. A supernova that may be the youngest black hole in Earth’s cosmic neighborhood has been discovered by a hobbyist. So take your chance.
