Winston
Lorenzo von Matterhorn
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Astronomers find source of stars' mysterious microwaves
For 20 years scientists have wondered what creates the curious streams of radiation in the Milky Way
https://www.theguardian.com/science...ource-of-stars-mysterious-microwaves-diamonds
Mysterious streams of microwaves that come from far across the galaxy have been traced to immense clouds of spinning diamonds that swirl around newly-born stars.
Astronomers have been stumped by the strange waves since they were first spotted more than 20 years ago, but now appear to have solved the puzzle after training US and Australian telescopes on rings of dust that circle stars about 500 light years from Earth.
Observations from the Green Bank Telescope in West Virginia and the Australia Telescope Compact Array in New South Wales found that the microwaves emanate only from stars which are surrounded by vast quantities of diamond particles which rotate tens of billions of times per second.
The diamond dust motes are only a millionth of a millimetre wide and so light that when they bump into each other they spin fast enough to emit microwaves which spread out across the universe, the scientists report in Nature Astronomy.
Researchers first became aware of what are called “anomalous microwave emissions” in 1996 when Nasa’s Cobe satellite created a full-sky map of radiation still visible from the big bang. The map revealed that some parts of the sky were inexplicably brighter in microwave frequencies than others.
At 0.75 to 1.1 millionths of a millimetre long, the diamond dust particles are vanishingly small. But Greaves estimates that stuck together, those around each star would weigh as much as the planet Mercury. When they are set spinning the particles emit microwaves because their electric charges are unevenly distributed, making one end of each nanodiamond positive and the other negative.
How the nanodiamonds are made in the first place is less clear, but they could form out of hot carbon vapour, or be thrown into space from exploding stars, where they drift and ultimately end up circling other newly-born stars.
Some tiny diamonds end up in meteorites and eventually make their way to Earth.
Then, there's the really big ones:
Cold Dead Star May Be a Giant Diamond
https://www.space.com/26335-coldest-white-dwarf-star-diamond.html
Astronomers aren't being poetic when they say this star is a diamond.
Scientists have identified what is possibly the coldest white dwarf ever detected. In fact, this dim stellar corpse is so cold that its carbon has crystallized, effectively forming a diamond the size of Earth, astronomers said.
"It's a really remarkable object," study leader David Kaplan, a professor at the University of Wisconsin-Milwaukee, said in a statement from the National Radio Astronomy Observatory (NRAO). "These things should be out there, but because they are so dim they are very hard to find."
For 20 years scientists have wondered what creates the curious streams of radiation in the Milky Way
https://www.theguardian.com/science...ource-of-stars-mysterious-microwaves-diamonds
Mysterious streams of microwaves that come from far across the galaxy have been traced to immense clouds of spinning diamonds that swirl around newly-born stars.
Astronomers have been stumped by the strange waves since they were first spotted more than 20 years ago, but now appear to have solved the puzzle after training US and Australian telescopes on rings of dust that circle stars about 500 light years from Earth.
Observations from the Green Bank Telescope in West Virginia and the Australia Telescope Compact Array in New South Wales found that the microwaves emanate only from stars which are surrounded by vast quantities of diamond particles which rotate tens of billions of times per second.
The diamond dust motes are only a millionth of a millimetre wide and so light that when they bump into each other they spin fast enough to emit microwaves which spread out across the universe, the scientists report in Nature Astronomy.
Researchers first became aware of what are called “anomalous microwave emissions” in 1996 when Nasa’s Cobe satellite created a full-sky map of radiation still visible from the big bang. The map revealed that some parts of the sky were inexplicably brighter in microwave frequencies than others.
At 0.75 to 1.1 millionths of a millimetre long, the diamond dust particles are vanishingly small. But Greaves estimates that stuck together, those around each star would weigh as much as the planet Mercury. When they are set spinning the particles emit microwaves because their electric charges are unevenly distributed, making one end of each nanodiamond positive and the other negative.
How the nanodiamonds are made in the first place is less clear, but they could form out of hot carbon vapour, or be thrown into space from exploding stars, where they drift and ultimately end up circling other newly-born stars.
Some tiny diamonds end up in meteorites and eventually make their way to Earth.
Then, there's the really big ones:
Cold Dead Star May Be a Giant Diamond
https://www.space.com/26335-coldest-white-dwarf-star-diamond.html
Astronomers aren't being poetic when they say this star is a diamond.
Scientists have identified what is possibly the coldest white dwarf ever detected. In fact, this dim stellar corpse is so cold that its carbon has crystallized, effectively forming a diamond the size of Earth, astronomers said.
"It's a really remarkable object," study leader David Kaplan, a professor at the University of Wisconsin-Milwaukee, said in a statement from the National Radio Astronomy Observatory (NRAO). "These things should be out there, but because they are so dim they are very hard to find."
