(Paradigm credit: NASA / Dana Berry)
More than one,200 years ago, some mysterious event was recorded in tree rings in a Japanese cedar forest.
While i report suggested a solar flare was to arraign, a new group of researchers are pointing toward a gamma-ray flare-up, a powerful space explosion.
The ancient cedar trees tape a rare event effectually 774 or 775 A.D. This shows up in a sharp rise in the amount of radioactive carbon-xiv and beryllium-10 recorded in the copse’ rings, which can be created by incoming particles from space.
But what caused an influx of radiation?
Tree ring mystery
According to astronomers Valeri Hambaryan and Ralph Neuhauser of the Astrophysics Constitute of the Academy of Jena in Germany, the most likely culprit was a gamma-ray burst. [Amazing Solar Flare of Oct. 22, 2012 (Photos)]
These bursts can be caused when two compact objects, such black holes or neutron stars, slam into each other and release a flood of high-energy gamma-ray radiations.
Such an interpretation, the scientists contend, fits the tree band mystery, because a gamma-ray burst would be powerful enough to cause the uptick in carbon-fourteen and beryllium-10. It also fits with the fact that no rare angelic upshot was observed that twelvemonth on Earth, at to the lowest degree co-ordinate to records bachelor at present.
The researchers calculated that a gamma-ray outburst at a distance of iii,000 and 12,000 low-cal-years from World all-time fits the data.
“If the gamma-ray flare-up had been much closer to the Earth it would have caused significant harm to the biosphere,” Neuhauser said in a argument. “Simply fifty-fifty thousands of light-years away, a similar consequence today could cause havoc with the sensitive electronic systems that advanced societies have come to depend on.”
The rare forms of carbon and beryllium, which are heavier than the normal varieties of those elements, are created when radiation from space collides with nitrogen atoms in Earth’south atmosphere, which then decay into carbon-xiv and beryllium-ten.
Both chemicals are unstable and decay on predictable time scales, allowing scientists to trace these item tree rings back to such a specific fourth dimension in the past. The fact that the leap in carbon-14 and glucinium-10 was merely seen in 1 year’s rings means whatever sparked their creation was short-lived.
“The challenge at present is to establish how rare such carbon-14 spikes are, i.due east., how often such radiation bursts hit the Earth,” Neuhauser said. “In the last iii,000 years, the maximum age of trees alive today, simply 1 such event appears to have taken place.”
The researchers say a gamma-ray burst explanation fits amend than a solar flare, because most flares from the sun would not be powerful enough to create such a fasten. Plus, they contend, a super-stiff solar flare would likely have created extra-special aurora displays, which were non seen, co-ordinate to historical records.
However, astrophysicists Adrian Melott of the University of Kansas and Brian Thomas of Washburn University say a flare would have to have been only nearly 10 or 20 times more powerful than the greatest flare on record, the so-called Carrington result of 1859. Since the records don’t go back very far, such an occurrence is not out of the realm of possibility, they say.
To distinguish betwixt the unlike interpretations, historians will accept to await for further hints in the historical records. Neuhauser and Hambaryan besides propose looking for the object that might have resulted from the merger that acquired the gamma-ray outburst, which would be a 1,200-yr-old black pigsty or neutron star that lies between 3,000 to 12,000 light-years away, but lacks the feature gas and grit clouds of a supernova remnant.
They report their findings Jan. 21 in the journal Monthly Notices of the Majestic Astronomical Lodge.
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