Thuban
42°
Recorded
α Draconis, former north pole star. The 42° on that plate is present Polaris as seen from ~42° N.
PhotoDavid RitterCC BY-SA 4.0
Thuban was the pole in the pyramid age. The present north, at 42°, is Polaris. Two stars. One latitude tautology.
What it supports
A named Stars-field cell. The 42 belongs to Polaris altitude ≈ observer latitude. Thuban is the former pole on the same plate.
What it does not
Thuban is not at 42°. Precession is not a 42-year clock. See Polaris at 42° for the measurement.
ExactnessCoordinate
Form42°
Unit°
Strengthattested