Imagined during the 18th century as part of Isaac Newton’s universal gravitation, black holes have since taken an important place in Pop Culture, and especially the 7th art. The spectators ofInterstellar possibly remember the representation of Gargantua, its gigantic black hole. And after managing to film a black hole swallowing a star in June 2018, now scientists have managed to record the “howl” of a star being swallowed.
a first
In September 2019, astronomers heard the “sound” of a newly formed black hole for the first time. An astonishing first considering a popular fact: no sound circulates in a vacuum. However, by isolating its sound signature, researchers have identified two distinct tones, corresponding to specific vibrational frequencies of the new black hole. A first listen that put the scientists on the right track.
#BlackHoleWeek = telescope teamwork!
In this new sonification, of the black hole in galaxy M87, multiple observations are represented as sound: Hubble (middle), X-rays from @chandraxray (top), and radio data from Atacama Large Millimeter Array (bottom): https:/ /t.co/xF81u82mWV pic.twitter.com/zFIyMpNroh
May 4, 2022
And at the beginning of May, NASA reveals a great first, that of the last moments of a star being swallowed by a black hole. Rather than sharing an image or an illustration of this very special moment with us, the American space agency wanted to innovate with an audio recording. And if this recording is possible, it is because a galaxy cluster containing hundreds of galaxies is surrounded by large amounts of gas. Thus, the sound waves can circulate, the opportunity for astronomers to capture and extract them, by increasing their frequency several million billion times, in order to make them audible to the human ear.
This galaxy cluster is the Perseus cluster. Located 250 million light-years from Earth, it has a black hole at its center. A black hole, one of whose meals, namely an unfortunate star, was recorded with the Chandra X-ray space observatory. A technical feat that allows us to represent a little more of the celestial objects that surround us, as well as how they work. A “sonification” (i.e. the “diffusion of a mechanical wave by gases, liquids, soft tissues, or solids, and whose frequency is greater than 20,000 Hz“) which should not be the last.
And for good reason, since 2003, the black hole located in the center of the Perseus cluster has been associated with these specific sound recordings. By analyzing this black hole, the astronomers discovered that the pressure waves emitted by it caused ripples in the hot gas of the cluster which could be translated into a musical note. Located 57 octaves below middle C, however, this note cannot be heard by the human ear. Nevertheless, once worked, this sonification can be shared with the general public. Next year, on the occasion of the week of the black holes of 2023, NASA will possibly share a new recording with us, in any case we hope.
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