Assertion: single flare | /r/HasProperty | responsible for the ad 774/5 event
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text: The most powerful flare which also had a hard spectrum that has been observed instrumentally took place in February 1956 (the beginning of nuclear testing obscures any possible effects in the 14C record); it has been estimated that if a single flare were responsible for the AD 774/5 event it would need to be 25-50 times more powerful than this.