775AD, update

The Usoskin and Kovaltsov paper at arXiv (see link on two posts previous to this one) is by two scientists who have previously written on the subject (2012, 2013) and appear to underestimate the ability of the coma of a comet being waggled by the solar wind. The necessity for a huge comet is assumed because in mainstream theory comets produce such effects due to heat (from the Sun) rather than from the electro-magnetic flux. Hence, it is likely the Chinese study won't too easily go away. It is backed up by a genuine observation. No records anywhere appear to record heightened aurorae as a result of a solar flare (the favoured theory of Usoskin and Kovaltsov). Usoskin et al (2013) 'The AD775 cosmic event revisited: the Sun is to blame' Ast. Astrophysics 552. Well, the Sun may very well be to blame – but not perhaps in quite the way imagined,