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For the first time, astronomers have captured solid evidence of a rare double cosmic cannibalism — a star swallowing a compact object such as a black hole or neutron star. In turn, that object gobbled the star’s core, causing it to explode and leave behind only a black hole.

The first hints of the gruesome event, described in the Sept. 3 Science, came from the Very Large Array (VLA), a radio telescope consisting of 27 enormous dishes in the New Mexican desert near Socorro. During the observatory’s scans of the night sky in 2017, a burst of radio energy as bright as the brightest exploding star — or supernova — as seen from Earth appeared in a dwarf star–forming galaxy approximately 500 million light-years away.

“We thought, ‘Whoa, this is interesting,’” says Dillon Dong, an astronomer at Caltech.

He and his colleagues made follow-up observations of the galaxy using the VLA and one of the telescopes at the W.M. Keck Observatory in Hawaii, which sees in the same optical light as our eyes. The Keck telescope caught a luminous outflow of material spewing in all directions at 3.2 million kilometers per hour from a central location, suggesting that an energetic explosion had occurred there in the past.

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Gravitational waves have brought us long-sought proof of a cataclysmic meeting between a black hole and a neutron star.

Are you in the mood to feel small? Like cosmically small? And not because of the usual dreamy, slightly cheesy stuff that space can offer—the idea that we exist on a tiny speck of rock clinging to our beautiful sun in the darkness. I’m talking about some truly wild action, so intense that it warps space-time, the invisible scaffolding that holds up everything we know, and reverberates for hundreds of millions of light-years.

Then astronomers have got something for you.

An international team of researchers announced today that it has detected evidence of one of the most extreme objects in the cosmos, a black hole, colliding with another of the most extreme objects in the cosmos, a neutron star, forming an even bigger black hole. And the team caught it happening not once, but twice.

Until now, these kinds of mergers, as astronomers call them, were purely hypothetical. Theoretical models predicted that they could, and should, happen. Astronomers had found evidence of other mash-ups between extreme astrophysical objects; in the past several years, they have detected mergers between two black holes and mergers between two neutron stars. But they couldn’t be certain that a meeting between one of each was possible, that nature could really bring them together, until one day, in a flash, the evidence arrived on Earth.

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Astronomers have gotten their first glimpse of the magnetic fields tangled around a black hole.

The Event Horizon Telescope has unveiled the magnetism of the hot, glowing gas around the supermassive black hole at the heart of galaxy M87, researchers report in two studies published online March 24 in the Astrophysical Journal Letters. These magnetic fields are thought to play a crucial role in how the black hole scarfs down matter and launches powerful plasma jets thousands of light-years into space (SN: 3/29/19).

“We’ve known for decades that jets are in some sense powered by accretion onto supermassive black holes, and that the in-spiraling gas and the outflowing plasma are highly magnetized — but there was a lot of uncertainty in the exact details,” says Eileen Meyer, an astrophysicist at the University of Maryland, Baltimore County not involved in the work. “The magnetic field structure of the plasma near the event horizon [of a black hole] is a completely new piece of information.”

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