The first “sleeping” black hole has been discovered outside our galaxy

Black holes have become commonplace in the media landscape in recent years and despite the riddles that still surround them and which touch on very deep questions about physical theoretically they are commonly considered in astrophysics and in cosmology. We even study their emissions of gravitational waves during collisions with others stars relativistic compressions. Most recently, we even got along radio telescopes images of their surroundings that betray the existence of what is believed to be one event horizonwhich is the very definition of a black hole when it is a closed surface.

Admittedly, we still evade conclusive proof of the existence of black holes. but the doubt of their presence in certain corners of The Milky Way and galaxies is becoming increasingly difficult to justify. What contrast with the early 1960s, when only a handful of visionaries, such as John Wheeler, took these solutions off equations of general theory of relativity seriously even Einstein did not do.

The first candidates for the title of black holes were nevertheless flushed out during the 1970s, in the form of a binary system where a star-sized hole, i.e. produced bycollapse the gravity of a star probably at least 30 masses sunbeams, also happened to be a strong source of x-rays upon accretion fabric from its compact star.

This substance, while falling in a spiral towards the black hole, actually forms a compact disc in which viscous frictional forces between the spirals of gas adjacent emerge from heat to the point of producing a bright hot plasma in the X-ray region.

Black holes are among the most opaque objects in the universe. Fortunately, however, they are among the most attractive, and it is by their exaggerated appeal that we can discover them. Giant black holes are the most monstrous ogres in the cosmic zoo, but they are not weapons of mass destruction. The rays of matter they produce would have helped ignite the first stars and form the first galaxies. Hubert Reeves and Jean-Pierre Luminet, specialists in modern cosmology, answer all your questions. Visit the site to find out more From the big bang to the living. © ECP Group, YouTube

However, we know that the majority of stars form binary systems, so we must expect that there are a certain number of these binary X in the Milky Way. However, it is also possible that the distance between a star-shaped black hole from its host star is such that no appreciable transfer of matter occurs. So no accretion disk and no X-ray emission, for example because the star has not yet become one red giant which has expanded to flow over what is called its Roche-lap, named after the mathematician, and astronomer 19th century Frenche century.

The first emerging tip of a population of dormant black holes

This kind of black star hole is said to be ” sleeping and so far no one had been discovered. That has just changed thanks to an international team of astronomers who used the Flames instrument for their discovery (Fiber Large Array Multi Element Spectrograph) on the VLT ofESOas the researchers explain in an article published in Nature astronomy.

To do this, they had to turn their gaze away from the VLT fog of the Tarantula located in Large Magellanic Cloud, a neighboring galaxy to our own. Six years of observations were needed for the team led by Tomer Shenar, who began this research at the University of Leuven in Belgium and who is now a Marie-Curie Fellow at the University of Amsterdam, in the Netherlands.

The sleeping black hole candidate has been christened VFTS 243. It contains at least nine times the mass of ours Sun and orbits a hot blue star that weighs 25 times the mass of the Sun. Remarkably, it is not accompanied by noticeable traces of remnants from an explosion of supernovasuggesting that as one thinks, a gravitationally collapsing star can sometimes directly turn into a black hole without going through the supernova stage.

The star that formed the black hole of the VFTS 243 appears to have completely collapsed with no sign of a previous explosionTomer Shenar explains in an ESO statement, in which he adds, Evidence for this “direct collapse” scenario has emerged recently, but our study undoubtedly provides one of the most direct indications. This has enormous consequences for the origin of mergers black holes in the cosmos. »

To get a fairly accurate French translation, click on the white rectangle at the bottom right. The English subtitles were then to be displayed. Then click on the nut to the right of the rectangle, then on “Subtitles” and finally on “Automatically translate”. Select “French”. © European Southern Observatory (ESO)

Interested in what you just read?

Leave a Comment