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A black hole located 55 million light years from Earth has recently been the first to be captured in a close-up image. In another first, he received a much more interesting name than those who usually identify black holes.
The new name, "Pōwehi", in native Hawaiian language, means "dark source embellished with eternal creation", and it was chosen by Larry Kimura, Hawaiian language teacher at the University of Hawaii, Hilo (UH), according to a statement. published by the university on April 10.
Kimura chose this name in collaboration with astronomers from two Hawaiian observatories that participated in the Event Horizon Telescope Project (EHT), the international collaboration behind the new black hole image. The Hawaiian words "pō" and "wehi" describe the concepts of ancient songs related to the creation of the Hawaiian universe, UH representatives said. [How Does a Black Hole Form?]
"Dark source embellished with endless creation" is certainly more evocative than the name commonly used for this black hole (or, in fact, for any black hole). Located in the heart of the Messier 87 galaxy (M87), the black hole in the image is usually called "M87 black hole" or "M87 *", the asterisk at the end indicating that it This is the center of the galaxy, experts. says Live Science.
Other names for M87 * are also strings of letters and numbers: NGC 4486, UGC 7654, Arp 152, and 3C 274. Although they have meaning for astronomers, they do not elicit the # Imagination as the names of planets, moons, asteroids, comets and other cosmic objects recalling gods or other figures of ancient mythologies.
Why do some celestial objects bear evocative and mythical names, while black holes – probably among the most mysterious and exciting of all cosmic phenomena – usually do not?
Official recognition
For any space object name to be officially recognized by astronomers worldwide, the nickname must first be approved by the International Astronomical Union (IAU), astronomer Morgan Hollis, spokesperson for the Royal Astronomical Society (RAS) in the UK, said Live Science in an email.
Founded in 1919, the IAU set up naming systems "so that objects can be unambiguously identified and everyone knows exactly what the object is in a given research paper," he said. Hollis.
But while these conventions exist for stars, planets, asteroids and others, no such protocol is still in place for black holes. This is partly because they were not directly observable until now, according to Hollis.
"Many theoretical studies were of course done, but the information was limited on specific black holes, so naming was not really a problem," he said.
Only a number
Before the creation of the IAU, many objects in space were widely known as numbers in catalogs created by astronomers such as Charles Messier, who lived in France in the late eighteenth century and at the beginning of the 19th century. Messier and others have documented their observations and numbered the objects sequentially, and other astronomers have begun to refer to these objects by their catalog numbers, said Vincent Fish, a researcher at Haystack Observatory's MIT in Boston, and part of the team that imaged the M87 black hole.
The Messier catalog, published in 1771, contains 110 objects; 87th in the list is the galaxy M87. But other catalogs exist alongside Messier, and many of their observations overlap, so the same galaxy – and the same black hole – can have multiple names, Fish told Live Science.
"It can be complicated sometimes when you know a source [of emissions] under a name and someone knows him by a different name, and it takes a while to understand that you are talking about the same source, "he explained.
The black hole of the M87, however, was already so well known that the Haystack Observatory EHT team had simply dubbed it "M87" or, occasionally, "3C 274" (they did not have any nickname particular, said Fish). [Historic First Images of a Black Hole Show Einstein Was Right (Again)]
What's in a name?
Over time, observations of more sensitive satellites have swollen the ranks of suspected black holes; those who did not have catalog names were usually designated by their spatial coordinates – "essentially, their longitude and latitude celestial" – called right ascension and declination, Michael Shara, curator and professor at the Department of Astrophysics of the American Museum New York's natural history, said Live Science.
These "names" of coordinates also include a few letters at the beginning to indicate which satellite has located the black hole, said Shara. And for now, this is the most practical approach to identification, because millions of X-ray sources could represent supermassive black holes, he said.
However, there is certainly a precedent for celestial objects to acquire more evocative names in addition to the letters and numbers of astronomers, according to Fish. For example, the M104 galaxy is commonly referred to as the Sombrero galaxy, because of its resemblance to a broad-brimmed hat, while the horse-like appearance of the nebula Barnard 3 gave it the name of Horsehead Nebula, at- he declares.
Now that the EHT has proven that it is possible to directly visualize a black hole, it may be time for the global community of astronomers to collectively reconsider how black holes will be named, Shara said.
However, even if Pōwehi begins to take shape as the new name of the black hole M87, it will not be considered official without the recognition of the IAU, according to Shara.
"If it must" stay ", it will require IAU support – but I think that's a good chance, because two of the radio telescopes involved in the work are based in Hawaii," Shara said.
As an official name, Pōwehi would not only honor the key instruments involved in the achievement, but also "the scientists and the local community who all work together and help make such groundbreaking scientific endeavors possible," said Hollis.
"The name will probably be decided by consensus in the scientific literature, if the IAU does not intervene," he added. "We will have to wait and see."
Originally published on Science live.
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