Europe had nearly the same view of the 1054 star as China
Astronomy Engine, Crab Nebula position. On the morning of 4 July 1054 (Julian), with the Sun 6 degrees below the horizon, the star stood 22 degrees up at Kaifeng, 19 at Rome and Constantinople, 13 at Cologne, 23 at Baghdad. It was 36 degrees from the Sun that day, 93 by 1 September, and opposite the Sun by 1 December (visible all night). No geometric reason for Europe to miss it.
How it connects
This clue from nature argues against
Europe missed the 1054 star because it was badly placed for European skies Europe's view was nearly as good as China's
This clue from nature is a clue for
Why did Europe barely record the supernova of 1054?
This clue from nature we read it in
Astronomy Engine (Don Cross), Python package; VSOP87 planets, ELP Moon. Used by scripts/odyssey_dates.py
This clue from nature came from this step
Checked whether Europe could see the 1054 supernova