The study hints at the presence of the closest black hole to Earth in the Hyades constellation

A paper published in a journal Monthly Notices of the Royal Astronomical Society hints at the presence of multiple black holes in the Hyades cluster – the closest open cluster to our solar system – which would make them the closest black holes to Earth ever discovered.

The results of the study from the collaboration between a group of scientists led by Stefano Torniamenti, University of Padua (Italy), with the important participation and Mark Gieles, ICREA professor at the Faculty of Physics, Institute of Cosmos Sciences of the University. of Barcelona (ICCUB) and the Institute of Space Studies of Catalonia (IEEC), and Friedrich Anders (ICCUB-IEEC).

In particular, the discovery took place during the research stay of the expert Stefano Torniamenti at the ICCUB, one of the research units that make up the IEEC.

Black holes in the Hyades cluster?

Since their discovery, black holes have been one of the most mysterious and fascinating objects in the universe and a subject of study for researchers around the world. This is especially true for small black holes because they have been observed during gravitational wave observations. Since the detection of the first gravitational waves in 2015, experts have observed several events associated with the merger of low-mass black hole pairs.

In a published study, a team of astrophysicists used measurements to track the movement and evolution of all the stars in the Hyades—located at a distance from the sun of about 45 parsecs or 150 light years—to reproduce their current state.

Open clusters are loosely bound groups of hundreds of stars that share certain characteristics such as age and chemical properties. The simulation results were compared to the actual positions and velocities of the stars in the Hyades, which are now precisely known from observations made by the European Space Agency’s (ESA) Gaia satellite.

“Our simulations can only match the mass and size of the Hyades if there are black holes present in the center of the cluster today (or until recently),” said Stefano Torniamenti, a postdoctoral researcher at the University of Padua and first author of the paper.

The observed properties of the Hyade are best reproduced by simulations with two or three black holes at the moment, although simulations in which all black holes have been ejected (less than 150 million years ago, about the last quarter of the group’s age) may still provide. good game, because the evolution of the group could not erase the traces of its former inhabitants in the black hole.

The new results show that the black holes born in the Hyades are still inside the cluster, or very close to the cluster. This makes them the closest black holes to the sun, much closer than the previous candidate (the so-called black hole Gaia BH1, which is 480 parsecs from the sun).

In recent years, the success of the Gaia telescope has made it possible for the first time to study the location and velocity of open star clusters in detail and to identify individual stars with confidence.

“These observations help us to understand how the presence of black holes affects the evolution of star clusters and how star clusters contribute to the wave sources,” said Mark Gieles, member of the UB Department of Quantum Physics and Astrophysics and lead author in Barcelona. “These results also give us insight into how these mysterious objects are distributed in the galaxy.”