Shaft alignments (claim C2)
For each shaft, the epoch at which the named star crossed the meridian at the shaft's measured altitude, from latitude 29°58′45″ N, using Vondrák 2011 precession and linear proper motion. "Years per arcminute" is how far the solved date moves if the measured shaft angle changes by 1′. Shaft angles are unverified Gantenbrink values; see data/measurements/g1.json.
| Shaft | Angle | Star | Culmination | Epoch | Years per 1′ of shaft angle |
|---|---|---|---|---|---|
| King's Chamber south | 45°00′00″ (gantenbrink-1993) | Alnitak | upper | 2492 BCE | 3.4 |
| King's Chamber north | 32°36′00″ (gantenbrink-1993) | Thuban | upper | 3261 BCE | 3.0 |
| King's Chamber north | 32°36′00″ (gantenbrink-1993) | Thuban | upper | 2333 BCE | 3.0 |
| Queen's Chamber south | 39°36′28″ (gantenbrink-1993) | Sirius | upper | 2368 BCE | 5.6 |
| Queen's Chamber north | 39°07′00″ (gantenbrink-1993) | Kochab | upper | 2380 BCE | 4.9 |
Bauval & Gilbert (1994) date all four to about 2450 BCE. A shaft whose solved epoch moves by decades per arcminute cannot date the pyramid to better than a century or two from its angle alone.