According to a new study, several black holes could exist within the Hyades Star Cluster, which is our solar system's closest open cluster. If this were the case, this would make those black holes the closest ones to Earth that have ever been found.
Could This Be Earth's Closest Black Holes?
The astrophysics team made use of simulations that monitor evolution and motions of all stars within the Hyades Cluster, which is situated around 150 light-years from the Sun. They did so to reproduce the stars' current state.
Open clusters refer to groups of stars that are hundreds in number and loosely bounded and share certain characteristics, including age and chemical properties.
The results of the simulation were then compared to Hyades stars' actual velocities and positions. These are now precisely and accurately known, thanks to the Gaia satellite of the European Space Agency.
Postdoctoral researcher Stefano Torniamenti from the University of Padua, who served as the study's first author, explains that the simulations are only capable of simultaneously matching the size and mass of Hyades if there are indeed some black holes situated in the cluster's center today or until recently.
The properties of Hyades that were observed are reproduced best with simulations of two to three present black holes, though simulations of ejected black holes could still result in a good match. This is due to how the cluster's evolution could not erase remnants of its black hole population in the past.
ALSO READ: Black Hole Twistiness? New Theory of Gravity Focuses on Energy, Mass Twists Rather Than Curvature
Black Holes in Hyades Cluster
The results show that black holes born in Hyades are still inside of or close to the cluster. As such, these findings indicate that these black holes are the closest to the Sun. In fact, they are significantly closer compared to their predecessor candidate, Gaia BH1.
That being said, the idea that black holes can be found within star clusters is not a new idea. Star clusters, which are large groups of hundreds of millions of stars that offer the astronomical world insights regarding stellar evolution, usually have huge and bright stars that will eventually evolve to become black holes or neutron stars. Hence, chances are that earlier stars could have already traversed down this path.
Unless black holes are feeding on material nearby, it may be hard to spot them in a bright star cluster. Because of this, astronomers need to utilize indirect observations for black hole detection and uncovering.
Star clusters are different from galaxies, which are cosmic entities that also comprise groups of stars that are gravitationally bound. What straightforwardly differentiates the two is whether the star groups are bound by their intrinsic gravity or if a dark matter is present to hold them together.
RELATED ARTICLE: Black Hole Jet Observations Shed Light on Particle Acceleration That Generates X-Rays
Check out more news and information on Space in Science Times.
