Analysis of tree rings reveals highly abnormal solar activity in the mid-holocene

By analyzing the level of a carbon isotope in tree rings from a specimen of an ancient bristlecone pine, a team led by Nagoya University researchers has revealed that the sun exhibited a unique pattern of activity in 5480 BC. By comparing this event with other similar but more recent phenomena, they reported that this event may have involved a change in the sun’s magnetic activity, or a number of successive solar burst emissions.