Astronomical record in trees

[Rothkko]

¿La existencia de carbono-14 en los anillos de los árboles es solo atribuible a un evento extraterrestre? Si es así, ¿cuál creen que pudo ser?
Computer translate:
Is the existence of carbon 14 in the rings of the trees alone attributablly to an extraterrestrial event? If it is like that, which do they believe that it could be?

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http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11123.html
http://www.newscientist.com/article/dn21878-vast-cosmic-event-leaves-record-in-ancient-trees.html?DCMP=OTC-rss&nsref=online-news
http://www.abc.es/20120604/ciencia/abci-misterioso-bombardeo-cosmico-siglo-201206040945.html

[Chris Peterson]

Is the existence of carbon 14 in the rings of the trees alone attributablly to an extraterrestrial event? If it is like that, which do they believe that it could be?

C-14 is primarily produced in the atmosphere by the action of cosmic rays, so in a sense we can attribute its presence to extraterrestrial events. But the actual rate of production depends on many things (in particular, the strength and orientation of Earth's magnetic field, which is quite variable). So when a C-14 spike is observed in tree ring data, it doesn't necessarily point to a specific extraterrestrial event, like a supernova. The C-14 level in the atmosphere (and therefore in biological samples) has been uneven over tens of thousands of years, and teasing out the specific things that produced that variation has largely eluded scientists so far.

[Rothkko]

So when a C-14 spike is observed in tree ring data, it doesn't necessarily point to a specific extraterrestrial event, like a supernova.

But it had to be something exceptional, in any case
Pero tuvo que ser algo excepcional, en cualquier caso.

[Chris Peterson]

So when a C-14 spike is observed in tree ring data, it doesn't necessarily point to a specific extraterrestrial event, like a supernova.

But it had to be something exceptional, in any case
Pero tuvo que ser algo excepcional, en cualquier caso.

I guess it depends on how you define "exceptional". There are a number of relatively prosaic things that could cause such a spike.

[Rothkko]

I guess it depends on how you define "exceptional". There are a number of relatively prosaic things that could cause such a spike.

Are exceptional absorption rates of C-14 about 24 times higher than normal in those two years.
Excepcional son tasas de absorción de C-14 unas 24 veces mayores de lo normal en esos dos años.

[Chris Peterson]

Are exceptional absorption rates of C-14 about 24 times higher than normal in those two years.

The absorption rate is 1.2% higher, not 24 times higher. The variation is described as about 20 times higher than the variation caused by the solar cycle.

It certainly seems as if something happened, but it need not have been more spectacular than a year of unusual solar activity. In any case, it warrants more study, and I'm sure that a few researchers are looking for additional evidence that could narrow down the possibilities.