Astral Core is at center a way of seeing the whole potential of an individual represented by the core of the horoscope. What was seeded at birth and took shape in development. Take the Sun-Moon blend, the condition of the Sun and Moon together with how each is placed in the chart, add in how each are aspected by other planets, and the consider any outstanding stand alone constructs. What we observe so often is a pattern that reverberates over and over again throughout the analysis of the chart and indeed throughout life development. A uniquely individuated personality.