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Astronomers Confirm First 'Lone' Black Hole Discovery - and It's in the Milky Way

2 months 1 week ago
For the first time, astronomers have confirmed the existence of a lone black hole," reports Science News — "one with no star orbiting it." It's "the only one so far," says Kailash Sahu, an astronomer at the Space Telescope Science Institute in Baltimore. In 2022, Sahu and his colleagues discovered the dark object coursing through the constellation Sagittarius. A second team disputed the claim, saying the body might instead be a neutron star. New observations from the Hubble Space Telescope now confirm that the object's mass is so large that it must be a black hole, Sahu's team reports in the April 20 Astrophysical Journal.... [And that second team has revised its assessment and now agrees: the object is a black hole.] While solitary black holes should be common, they are hard to find. The one in Sagittarius revealed itself when it passed in front of a dim background star, magnifying the star's light and slowly shifting its position due to the black hole's gravity. This passage occurred in July 2011, but the star's position is still changing. "It takes a long time to do the observations," Sahu says. "Everything is improved if you have a longer baseline and more observations." The original discovery relied on precise Hubble measurements of star positions from 2011 to 2017. The new work incorporates Hubble observations from 2021 and 2022 as well as data from the Gaia spacecraft. The upshot: The black hole is about seven times as massive as the sun, give or take 0.8 solar masses.... Located 5,000 light-years from Earth, this black hole is much closer than the supermassive one at the Milky Way's center, which also lies in Sagittarius but about 27,000 light-years from us. The star-rich region around the galactic center provides an ideal hunting ground for solitary black holes passing in front of stars. Sahu hopes to find additional lone black holes by using the Nancy Grace Roman Space Telescope, slated for launch in 2027.

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EditorDavid

Conservationists Say 'De-Extinction' Not the Answer to Saving Extinct Species

2 months 1 week ago
There was excitement when biotech company Collosal announced genetically modified grey wolves (first hailed as a "de-extinction" of the Dire wolf species after several millennia). "But bioethicists and conservationists are expressing unease with the kind of scientific research," writes the Chicago Tribune. [Alternate URL here.] "Unfortunately, as clever as this science is ... it's can-do science and not should-do science," said Lindsay Marshall, director of science in animal research at Humane World for Animals, formerly the Humane Society of the U.S.... Ed Heist, a professor at Southern Illinois University and a conservation geneticist, said the news bothered him. "This is not conservation, but people conflate it," he said. "The point is entertainment...." Naomi Louchouarn [program director of wildlife partnerships at Humane World for Animals], has dedicated her studies and research to the relationship between humans and animals, specifically carnivores like gray wolves. "The reason our current endangered species are becoming extinct is because we don't know how to coexist with them," she said. "And this doesn't solve that problem at all." Humans can treat the symptoms of wildlife conflict with "big, flashy silver bullets" and "in this case, advanced, inefficient science," she said, but the real solution is behavioral change. "Assuming that we could actually bring back a full population of animals," Louchouarn said, "which is so difficult and so crazy — that's a big if — I don't understand the point of trying to bring back a woolly mammoth when we already can't coexist with elephants." The article notes that even Colossal's chief science officer says their technology is at best one of several tools for fighting biodiversity loss, calling it a battle which humans are 'not close to winning'... We as a global community need to continue to invest in traditional approaches to conservation and habitat preservation, as well as in the protection of living endangered species." But the article adds that the Trump administration "is citing the case of the dire wolf as it moves to reduce federal protections under the Endangered Species Act of 1973." (Wednesday U.S. interior secretary Doug Burgum has even posted on X "The concept of 'de-extinction' can serve as a bedrock for modern species conservation.") And the article adds that "During a livestreamed town hall with Interior Department employees on April 9, Burgum said: "If we're going to be in anguish about losing a species, now we have an opportunity to bring them back. Pick your favorite species and call up Colossal. Ken Angielczyk, curator of mammal fossils at the Field Museum who researches extinct species that lived 200 to 300 million years ago, said it's a misguided approach. "If that's the basis ... for changing regulations related to the endangered species list, that is very, very premature," he said. "Because we can't resurrect things.... If the purpose is to restore the damage to the shared ecosystem, we have that opportunity right now," she said. "And that's the necessity immediately...." "This whole idea that extinction is reversible is so dangerous," Marshall said, "because then it stops us caring." Thanks to long-time Slashdot reader walterbyrd for sharing the news.

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EditorDavid