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Western astrology system guide

Western Astrology Knowledge Base

Learn Western astrology through reproducible chart calculation, planets, signs, houses, aspects, synthesis, timing, relationships, methods, and evidence limits.

Canonical name
Western astrology
Chart terms
birth chart · natal chart · horoscope chart
Chinese
西方占星术 · 西洋占星學
Japanese
西洋占星術 · 出生図 · ネイタルチャート
Korean
서양 점성술 · 출생 차트 · 네이털 차트

Editorially reviewed: · Reviewed by OpenFate · Editorial Methodology

Overview

Western astrology maps astronomical positions into a symbolic chart language. This Wiki separates reproducible chart facts from interpretive tradition, declares every material setting, and teaches how to synthesize evidence without treating symbolism as scientific proof or a fixed outcome.

At a glance

Current OpenFate zodiac
Tropical zodiac; not sidereal or Vedic
Current OpenFate house system
Placidus, with explicit birth-time and latitude confidence gates
Current OpenFate position source
Swiss Ephemeris with versioned product policy
Core grammar
Planet or point → zodiac sign → house → aspects → condition → timing layer
Professional branches
Natal, relationship, predictive, locational, horary, electional, and mundane astrology
Evidence boundary
Calculations are reproducible; symbolic interpretations are a tradition, not established scientific predictions

Explore concepts

Calculate first, interpret second

A birth chart begins with a civil date, clock time, named time zone, historical offset, birthplace coordinates, and a declared astronomical policy. Those inputs are converted to one instant and used to calculate ecliptic positions, angles, houses, motion, and aspect geometry.

OpenFate records the zodiac mode, house system, lunar-node policy, ephemeris source, engine version, latitude limits, and time confidence. If a birth time is missing or unreliable, the Wiki explains which outputs remain usable and which angle- or house-dependent claims must stop.

  • Reproduce the chart before comparing interpretations.
  • Do not hide tropical, sidereal, house-system, node, orb, or coordinate choices.
  • Treat longitude, house, aspect, and speed as chart facts; treat meaning as a separate claim.

Separate the layers of chart grammar

Planet pages define the body or symbolic actor. Sign pages define a zodiac-sign quality. House pages define a chart field. Placement pages explain a combined configuration, such as Venus in Scorpio or Saturn in the seventh house. Pair pages explain the relationship between two planets and distinguish aspects that are geometrically possible in one natal chart from aspects available only in transit-to-natal or synastry geometry.

This separation prevents sign, Sun-sign, planet, and placement explanations from repeating the same answer. Overview pages teach the rule and guide the reader; specific placement pages handle the distinct configuration and its modifiers.

  • A zodiac sign is a 30-degree symbolic division, not the same thing as an IAU constellation.
  • A planet pair must distinguish natal geometry from transit-to-natal and synastry geometry.
  • An outer-planet sign placement requires generational dates and historical context before personal interpretation.

Read the whole chart in an auditable order

Start with input confidence and chart settings. Identify the luminaries, Ascendant when reliable, chart ruler, angularity, sect, dignity, elemental and modal balance, house rulers, major aspects, and repeated themes. Only then add timing, relationship, relocation, or specialized traditional techniques.

A strong reading shows which chart facts support a statement, what weakens it, which school supplied the rule, and what remains unknown. Empty houses, interceptions, retrogrades, aspect patterns, and dominant-planet heuristics are modifiers rather than automatic verdicts.

  • Prioritize repeated independent evidence over a single dramatic symbol.
  • Keep natal, transit, synastry, return, progression, and election charts in separate layers.
  • Record a counterexample or stop rule before turning a symbolic theme into advice.

Keep methods and schools explicit

Modern psychological, traditional Hellenistic and medieval, humanistic, evolutionary, Western sidereal, Uranian, and cosmobiological approaches do not share every rule. Horary, electional, and mundane astrology also use different chart questions and judgement procedures from natal astrology.

The Wiki therefore names the method, separates common calculation facts from attributed doctrine, and marks techniques that the current OpenFate product does not compute. Historical inclusion documents a tradition; it does not validate a predictive claim.

  • Do not blend incompatible rulership, orb, house, dignity, or timing policies silently.
  • Do not present a curriculum or classical text as scientific validation.
  • Do not imply that an unsupported OpenFate feature was calculated for a personal chart.

Use evidence, consent, and a bounded product loop

Astrology is a historical and cultural interpretive practice whose predictive and personality claims are not established by scientific evidence. OpenFate can calculate positions and organize symbolic questions, but it must not guarantee events, diagnose health, replace legal or financial advice, or remove a person’s agency.

Each topic explanation links to related definitions and exact source locators. Where the current product supports the method or configuration, the page also links an appropriate chart or reading tool. The tool verifies whether a configuration is present; the reader returns to the explanation to review the rule, uncertainty, school scope, and alternatives before acting.

  • Use consented data and disclose birth-time quality, especially for public figures and relationship charts.
  • Separate reflection from medical, legal, financial, safety, or mental-health decisions.
  • Keep the loop checkable: question → definition → calculation → evidence → boundary → next related rule.

Sources and editorial basis

  1. Faculty of Astrological Studies: Foundation Course
    Foundation Course, H2 “Module 1: Introduction to Astrology: Planets, Signs and Houses”, H2 “Module 2: Chart Skills I”, H2 “Module 3: Chart Skills II”, and H2 “Foundation Practice Module (three months tuition time)”; Module 1 key topics cover planets, zodiac signs, and twelve houses, while Module 2 covers aspects and aspect patternsA practitioner curriculum used to scope the chart vocabulary and the order in which planets, signs, houses, aspects, patterns, and synthesis are taught; it is not scientific validation.
  2. Swiss Ephemeris Programmer’s Manual
    Swiss Ephemeris documentation, sections 6–7 and programmer-interface sections 15–17: sidereal time, Ascendant, MC, houses, polar limits, and Delta TThe Swiss Ephemeris programming manual used for geocentric ecliptic positions, Julian-day inputs, house cusps, and Ascendant/MC calculations. Numerical positions are reproducible outputs; symbolic meanings are a separate tradition.
  3. IANA Time Zone Database
    IANA Time Zone Database and theory file: named zones, historical offsets, civil-time changes, and daylight-saving transitionsThe maintained source for current and historical civil-time offsets and daylight-saving transitions; it provides timekeeping facts, not astrological interpretation.
  4. Organization for Professional Astrology: Code of Ethics
    OPA Code of Ethics §1(b) Confidentiality, §1(g) Sexual, Financial & Other Boundaries, §1(i) Integrity of Services Offered, §1(j) Fatalistic Statements and client autonomy, §2(f) Scope of Practice and referral, and §2(g) Integrity with Public Figures’ ChartsAn independent practitioner code covering accurate data, confidentiality, client welfare, informed practice, competence, and referral boundaries.
  5. Nature: A Double-Blind Test of Astrology
    Nature 318 (1985), pp. 419–425: double-blind natal-chart matching protocol, results, and evidentiary limitsThe 1985 double-blind natal-chart matching study, used with its exact design, target claim, sample, outcome, and later methodological discussion—not as a slogan.
  6. OpenFate Calculation and AI Validation Disclosure
    Calculation Validation stable sections #calculation-interpretation, #verification-controls, and #methodology-limits: public calculation-first workflow, verification, and interpretation limits. This page does not enumerate every Western-astrology setting; the exact defaults below describe current OpenFate product policy.OpenFate’s public calculation-first method separates normalized birth inputs, reproducible chart results, AI-assisted explanation, verification, and limits. It does not list every Western-astrology setting; check the current feature or support page for available calculations.

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