How to calculate precession - an example
Bellatrix is now conjunct Gemini 21. When was Bellatrix conjunct Gemini 3?
- From Gemini 3 to Gemini 21 is 18 degrees.
- At a rate of approximately 1 degree every 72 years, it would take about 18 * 72 = 1,296 years to move from Gemini 3 to Gemini 21.
If we subtract 1,296 years from the current year (2025), we get:
2025 - 1296 = 729 CE.
Note: the exact aspect is around 24 June 723 CE.