I would tend to go with the principle of least astonishment when it comes to the 14C signal. We know the sun is capable of producing large flares such as the Carrington event. Melott & Thomas [www.nature.com] demonstrated that it need only take a flare that is only moderately larger (20 times the Carrington event if I remember correctly) than the Carrington event, or indeed a series of large flares over an extended period of time to create the signal, opposed to a single large transient gamma ray event. There is also a paper to appear in the Astrophysical Journal Letters (pre-print here [arxiv.org]) which discusses the idea that a large comet colliding with the sun could release high energy flares that could also explain the 774/775 event. So I wouldnt rule out events in our own solar system before looking further a field.

These hypotheses tend to be suggested because of a lack of historical records of any supernova event at that time, but to me there seems to be a flaw in the logic of assuming that just because one is not recorded does not mean that one did not occur. As discussed previously the event may have been recorded in the source material for the Anglo-saxon Chronicles and Roger of Wendower (even though they seem to disagree by a year or two). For example, Roger gives the description of

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“In the year of our Lord 776, fiery and fearful signs were seen in the heavens after sunset ; and serpents appeared in Sussex, as if they had sprung out of the ground, to the great astonishment of all”

But according to the Anglo-Saxon Chronicle in 774

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“This year the Northumbrians banished their king, Alred, from York at Easter-tide; and chose Ethelred, the son of Mull, for their lord, who reigned four winters.
This year also appeared in the heavens a red crucifix, after sunset; the Mercians and the men of Kent fought at Otford; and wonderful serpents were seen in the land of the South-Saxons.”

Similarly, Roger has this to say about the year 794

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“In the year of our Lord 794, Humbert, archbishop of Lich field, died, and was succeeded by Higbert. The same year dreadful prodigies terrified the miserable English nation ; for fearful thunderbolts and horrible fiery dragons were seen passing through the air, foreboding a mighty famine and dreadful slaughter of the people. For the Danes with the Norwegians committed sad havoc among the people of Northumberland and of Lindesfarne, destroying the churches of Christ with their inmates. The island of Lindisfarne, which has an extent of eight miles or more, contains a noble monastery, in which was buried the illustrious father, bishop Cuthbert, with other prelates, his most holy successors. Now the Lindis is a rivulet, flowing into the sea, and is about two feet in width at low tides, but at high tides it cannot be seen.”

While the Anglo-Saxon Chronicle has this to say in 793

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“In this year dire portents appeared over Northumbria and sorely frightened the people. They consisted of immense whirlwinds and flashes of lightning, and fiery dragons were seen flying in the air. A great famine immediately followed those signs , and a little after that in the same year, 8 June, the reavers of the heathen men miserably destroyed God’s church in Lindisfarne, with plunder and slaughter. And Sicga died on 22 February.”

From the recent Gamma ray burst paper, from my understanding of the paper, the researchers were looking for a mechanism that could generate gamma rays without a visible supernova. The issue seems to be the belief that no supernova was observed/recorded at the time, hence the different hypothesised scenarios. Indeed, in the outset of the recent paper, the authors construct their argument that a supernova capable of producing enough gamma rays to explain the 14C excess should have been within 260 parsecs (about 850 light years), and so should have been visible. In order for it to remain undetected there would have to be extreme optical absorption, which would be impossible for the distance, ergo it was not an ordinary supernova, and must have been something else. But what if it was observed and recorded, for example in the sources of Roger of Wendower or the Anglo-Saxon Chronicle, or has not been recognised as being recorded, then a normal supernova should still be on the table.

So while I think that we should not abandon looking to our Sun as the source, so too I dont think we should through out the idea that it may have been a bog standard supernova.

Jonny

The path to good scholarship is paved with imagined patterns. - David M Raup