discovered by astronomers the closest known black hole to Earth, just 1,600 light years away.
Scientists reported Friday that this black hole is 10 times bigger than our Sun, and it is three times closer than what was considered the closest.
It was identified by observing the motion of its companion star, which orbits the black hole at roughly the same distance as the Earth orbits the Sun.
The black hole was initially identified using the Gaia probe of the European Space Agencysaid Karim El-Badry of the Harvard-Smithsonian Center for Astrophysics.
El-Badry and his team followed the International Gemini Observatory in Hawaii to confirm their findings, which were published in the Royal Astronomical Society’s monthly announcements.
Researchers aren’t sure how the system formed in the Milky Way. Called Gaia BH1, It is located in the constellation of Ophiuchus.the snake bearer.
Does it have risks for the solar system?
Called Gaia BH1the black hole is the corpse of an extinct star. According to the theory of stellar evolution, stars much larger than the Sun die in a huge explosion creating a supernova before becoming black holes. In this case, the original star had a mass of at least twenty times larger than the sun.
What puzzles the authors of the discovery is that the still visible star revolving around them completes one orbit every 186 daysaccording to the data published in the journal Royal Astronomical Society Monthly Notices. This implies that the star is at a distance from the black hole no greater than that from the Sun to the Earth.
But if the large star from which the black hole formed had exploded as a supernova, it would have swallowed this second star so close. “How this system was formed is uncertain”, acknowledges the authors of the research in the scientific article. But they add that “we have not found any plausible astrophysical scenario that could explain the orbit that does not involve a black hole.”
Therefore, they conclude that “this is the closest black hole” and that “its discovery suggests the existence of a considerable population of black holes (…) in binary star systems”. The closest previously known black hole is located three times farther in the constellation of Monoceros, the researchers report.
It does not emit X-rays
The vast majority of black holes discovered so far have been detected why cause a powerful X-ray emission capturing matter from a nearby star. The new star, on the other hand, is an inactive black hole. It no longer absorbs matter and emits no X-rays, so it is more difficult to see.
The first indication of its existence was provided by the European Gaia Space Telescope, which detected irregularities in the movement of a visible star apparently caused by the gravity of an invisible object.
To study the system in more detail, astronomers turned to the Gemini North telescope in Hawaii. The visible star turned out to be very similar to the Sun.both for its mass (93% of the solar mass), and for its surface temperature (5,850 degrees Kelvin) and its metal content (analyzed with a spectrograph).
Sources: AP and La Vanguardia
Source: Clarin
