Placidus House System
Placidus House System is the most commonly used house system. House boundaries have unequal degrees and are sensitive to latitude differences.
Related Terms
Whole Sign Houses
One of the oldest house systems. A simple and effective system where each entire sign corresponds to one house. Common in Hellenistic astrology.
Orb
The acceptable deviation from an aspect's exact degree value. For example, a conjunction with a 5° orb is valid within ±5° of 0°.
IC (Nadir)
The lowest point of the chart, opposite the MC. The point representing roots, home, family, and your most private inner world.
Degree
The unit of measurement for determining positions on the zodiac circle. The 360° circle is divided into 12 signs of 30° each. Each degree can carry individual meaning.
Midheaven (MC)
The highest point of the chart, the middle of the sky. Represents your career purpose, social reputation, and public identity.
Ephemeris
An astronomical table showing the daily positions of planets. The fundamental reference source for astrologers' chart calculations.