The Discovery of the Closest Black Hole: A New Cosmic Revelation
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Chapter 1: Understanding Black Holes
The realm of black holes has evolved significantly over the years, especially as new findings emerge. Recently, I reported on the identification of the smallest black hole to date. Prior to that, I discussed the detection of one of the largest black holes ever observed.
Black holes are frequently formed, particularly when massive stars undergo supernova explosions and collapse in on themselves. These intense regions of gravity vary widely in size, encompassing everything from small and intermediate-mass black holes to supermassive and ultramassive ones. Typically, they reside in the centers of galaxies.
A prime example is Sagittarius A*, the supermassive black hole at the heart of the Milky Way, situated about 26,000 light-years from Earth and boasting a mass approximately 4 million times that of our sun. Now, we can add another groundbreaking discovery to our catalog: an international group of astronomers has identified the closest black holes to Earth.
Black holes, by their very nature, are shrouded in darkness and lack any emitted light, making them invisible to traditional telescopes. However, when they consume the remnants of dying stars, they can emit detectable light. This latest discovery was facilitated by the MPG/ESO 2.2-metre telescope located at ESO’s La Silla Observatory in Chile.
“An invisible object with a mass at least 4 times that of the Sun can only be a black hole. There must be hundreds of millions of black holes out there, but we know about only very few.” ~ Thomas Rivinius, Lead Author
Initially, the team of astronomers was studying the binary star system HR 6819. Closer inspection of the data uncovered the presence of a third, invisible object that the two stars appeared to orbit. Remarkably, this system is visible to the naked eye in the Southern hemisphere.
Determining the nature of this unseen object was challenging, but scientists concluded it had to be a black hole, given its mass of at least four solar masses. The object did not display the typical signs associated with black holes, leading researchers to detect it by observing the gravitational influence it had on the two stars.
By analyzing the orbits of the stars, scientists estimated the black hole's mass. The innermost star orbits the hidden body every 40 days, while the outer star follows a more distant path around the pair. The black hole found in HR 6819 stands out as one of the first stellar-mass black holes identified that does not engage violently with its surroundings, making it particularly elusive.
Building on this research, astronomers have also uncovered preliminary evidence of another system, designated LB-1, which similarly comprises three celestial bodies. The team believes this discovery may just be the beginning, with many more black holes of planetary mass potentially hidden within binary star systems.
Complete findings from this research were published in the journal Astronomy and Astrophysics. Stay updated with the latest developments by joining my mailing list.