[ad_1]
Astronomers who follow the data of thousands of distant stars have arrived at an astonishing conclusion: every 2000 to 3000 years, stars like the sun can produce super-surfaces a hundred times larger than anything recorded in the history of humanity.
Such an event, if it happened today, would produce a radiation explosion that would destroy satellites, disrupt electronics, disable communications, and devastate power grids around the world.
"Our study shows that super-events are rare events," says Yuta Notsu, a visiting scholar at the University of Colorado at Boulder, USA, "but it's possible we could experience such an event in the next 100 years ".
The troubling discovery comes from the study of data collected by the Kepler Space Telescope, designed to continuously monitor a field of about 150,000 distant stars.
Its primary mission is to search for changes in brightness caused by the silhouettes of planets passing in front of their suns. But the same data also allows scientists to collect huge amounts of data on the surges of these stars.
The eruptions are sudden releases of energy that we think caused by magnetic energy releases stored near the stars, the extrasolar equivalent of sunspots. Superflars are simply big versions.
According to conventional wisdom, the super-surfaces are the product of fast-moving young stars, unlike the sun which, in the Middle Ages, saw its rotation slow down about once every 25 days.
But it turns out that as the stars age and slow down, they do not stop having flares. They just have them less often.
"Young stars have supercultures every week or so," Notsu says. "For the sun, it's on average every few thousand years."
Nobody knows when or if the next superflare of this type will reach Earth.
The largest rocket recorded is the Carrington Event, a giant flare observed by English astronomer Richard Carrington in 1859, who created the northern lights as far south as Hawaii and southern aurora as far north as Santiago, Chile – slightly farther north than the city Australian Sydney.
Residents of the northeastern United States claimed that they could read the newspaper in the light of the dawn. The telegraph operators then reported sparks spurting out of their equipment, melting wires and lighting fires.
But according to superflare standards, the Carrington event was just a baby, Notsu recently said at a meeting of the American Astronomical Society (AAS) in St. Louis, Missouri.
His estimated energy was "simply" 1033 ergs – the equivalent of a thermonuclear explosion of 100,000,000,000 megatonnes.
The mammoths observed by the team of Notsu are immensely larger, which suggests that stars like the sun are capable of producing shrapnel of 1035 ergs every few thousand years – a hundred times bigger than the Carrington event.
"So we have no record of a rocket as big as the one you're describing, which means it's coming," AAS press officer Rick Fienberg told a recent conference. press organized by Notsu.
This does not mean, however, that it is impossible to determine whether the sun has ever produced such eruptions. This is because their radiation would create a carbon peak 14 in the upper atmosphere.
Carbon 14 is a form of radioactive carbon that, like the ordinary form, is found in biological tissues. It is formed when a highly energetic radiation from outer space produces neutrons in the upper atmosphere. These are captured by nitrogen 14, which then decomposes to carbon 14.
A 2012 study in Nature found a peak in carbon-14 levels in tree rings, suggesting that something, possibly a massive solar eruption, was sending carbon-14-forming radiation into the upper atmosphere of the Earth as recently as 775 AD.
"Such events can be used to investigate long-term [solar] activity, "says Notsu.
In the meantime, he adds, it may be wise to prepare by protecting the electronics on the ground and in orbit against massive surges.
"If a superflare happened 1000 years ago, it was probably not a big problem. People can [simply] have seen a great dawn. Now it's a much bigger problem because of our electronic components. "
In addition to being presented at the ASA meeting, Notsu's research was published in The astrophysical journal.
[ad_2]
Source link