The black hole Sagittarius A*, viewed in polarised light<\/p>\n
European Southern Observatory (ESO)<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
This is the supermassive black hole at the centre of our galaxy as we have never seen it before. The image reveals the swirling magnetic fields around Sagittarius A* (Sgr A*) and hints that it may be producing a jet of high-energy material, which astronomers have yet to see.<\/p>\n
The picture was taken by a network of observatories around the world operating as a single, giant telescope, called the Event Horizon Telescope (EHT). In 2022, it produced the first image of Sgr A*, revealing light coming from whirling hot plasma set against the dark background of the black hole\u2019s event horizon, where light can\u2019t escape its extreme gravity.<\/p>\n
Now, EHT researcher Ziri Younsi at University College London and his colleagues have measured how this light is polarised, or the orientation of its electromagnetic field, showing the direction and strength of the magnetic field around Sgr A*.<\/p>\n
The image is remarkably similar to the magnetic field of M87*, the first black hole EHT studied. Given that M87* is around 1500 times more massive than Sgr A*, it suggests that supermassive black holes may have similar structures regardless of their size, says Younsi.<\/p>\n The two black holes imaged by the Event Horizon Telescope look surprisingly similar<\/p>\n European Southern Observatory (ESO)<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n <\/p>\n One major difference between M87* and our galaxy\u2019s black hole is the lack of visible high-energy jets seen from Sgr A*. This absence has long puzzled astronomers, but the fact that Sgr A* has a magnetic field like M87* suggests that there could be jets in our galaxy\u2019s black hole, too.<\/p>\n \u201cThere\u2019s this really exciting hint that there may be some additional structure,\u201d says Younsi. \u201cThere might be something going on that\u2019s quite exciting in the centre of the galaxy, and I think that these results we\u2019re going to need to follow up.\u201d<\/p>\n This would make sense given other pieces of evidence we see for a jet that may have existed long ago in our galaxy\u2019s history, such as the Fermi bubbles, large spheres of X-ray-producing plasma above and below the Milky Way.<\/p>\n \n ![\"\"](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/03\/27111343\/SEI_197607577.jpg?width=1200\")
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