  The interpretation of the strong 14-C variation around AD 775 as one (or
several) solar super-flare(s) by, e.g., Usoskin et al. (2013) is based on
alleged aurora sightings in the mid AD 770s in Europe: A "red cross/crucifix"
in AD 773/4/6 from the Anglo-Saxon Chronicle, "inflamed shields" in AD 776
(both listed in the aurora catalogue of Link 1962), and "riders on white
horses" in AD 773 (newly proposed as aurora in Usoskin et al. 2013), the two
latter from the Royal Frankish Annals. We discuss the reports about these three
sightings in detail here. We can show that all three were halo displays: The
"red cross" or "crucifix" is formed by the horizontal arc and a vertical pillar
of light (either with the Sun during sunset or with the moon after sunset); the
"inflamed shields" and the "riders on white horses" were both two mock suns,
especially the latter narrated in form of a Christian adaptation of the antique
dioscuri motive. While the latter event took place early in AD 774 (dated AD
773 in Usoskin et al. 2013), the two other sightings have to be dated AD 776,
i.e. anyway too late for being in connection with a 14-C rise that started
before AD 775. We also sketch the ideological background of those sightings and
there were many similar reports throughout that time. In addition, we present a
small drawing of a lunar halo display with horizontal arc and vertical pillar
forming a cross for shortly later, namely AD 806 June 4, the night of full
moon, also from the Anglo-Saxon Chronicle; we also show historic drawings of
solar and lunar halo crosses from G. Kirch and Helevius and a modern
photograph.
