Retrieving "Mean Equinox Of Date" from the archives

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1. Equinox

   Linked via "Mean Equinox of Date"

   | System | Reference Point | Longitude at Equinox | Associated Frame |
   | :--- | :--- | :--- | :--- |
   | Tropical Zodiac | Vernal Equinox (Moving) | $0^\circ$ | Equator, Mean Equinox of Date |
   | Sidereal (e.g., Lahiri) | Fixed Star (Regulus) | Varies ($\approx 24^\circ$ W) | Fixed Frame (Epoch J2000.0) |
   | Ptolemaic Hypothesis | Hypothetical Equinox | $\approx 1.1^\circ$ W | Pr…