Western Astrology · Tropical

Everything Western astrology can calculate for you

650+ techniques from Ptolemy to Ebertin: natal, progressions, directions, synastry, fixed stars and Hellenistic lots. Every calculation cites its primary source.

143fixed stars
360Sabian symbols
106midpoints

Cited from Ptolemy and Lilly

Every calculation links to a primary source: Ptolemy's Tetrabiblos, William Lilly's Christian Astrology, Vettius Valens' Anthology, the works of Robson and Brady.

NASA JPL precision

Swiss Ephemeris (DE431 / NASA JPL) under the hood — the same astronomy NASA uses, no rounding, no approximations.

Hellenistic + Modern schools

From 2nd-century profections and Zodiacal Releasing to Dane Rudhyar's Sabian symbols and Ebertin midpoints. Full spectrum of traditions.

Calculation catalog

12 sections of Western astrology

Open a section to see the techniques inside, each with a one-line description and source reference.

12 zodiac signs

Tropical zodiac: 12 equal signs of 30°, anchored to the equinox points.

10 planets + nodes

Personal, social and transpersonal planets + North/South lunar nodes.

12 houses

Life domains: from body (1st) to subconscious (12th).

ASC / MC / DSC / IC

Four angular points — primary axes of personal identity.

Elements

Fire, Earth, Air, Water — energetic balance of the chart.

Modalities

Cardinal, Fixed, Mutable — modes of action.

Polarities

Yang (fire + air) and Yin (earth + water) — active vs receptive balance.

Hemispheres

Planet distribution across chart halves — private vs public emphasis.

Chart shape (Marc Edmund Jones)

7 types: Bowl, Bucket, Locomotive, Seesaw, Splay, Splash, Bundle — pattern of planet distribution.

Chart signature

Strongest sign by weighted planet score — the chart's primary note.

Focal planet

The Bucket-chart 'handle' or a singleton — primary energy channel.

Sources: Ptolemy Tetrabiblos · Lilly Christian Astrology · Marc Edmund Jones "How To Learn Astrology" · Liz Greene · Stephen Arroyo

Major aspects

Conjunction, sextile, square, trine, opposition — Ptolemy's five.

Minor aspects

Semi-sextile, quintile, septile, novile, biquintile and others.

Aspect patterns

Stellium, T-square, Grand Trine, Grand Cross, Yod, Kite.

T-Square

Two oppositions + square — the chart's primary tension.

Grand Trine

Three trines in one element — easy talent.

Yod (Finger of God)

Two quincunxes + sextile — karmic mission point.

Kite

Grand Trine + opposition to a fourth planet — talent focus.

Orbs

Allowable deviation from exact angle — adjustable by school.

Mystic Rectangle

2 oppositions + 2 trines + 2 sextiles — harmonious stable figure.

Cradle

3 sextiles + 2 trines — supportive, protecting configuration.

Stellium

3+ planets in one sign or house — theme concentration.

13 aspect figures

Full catalog: T-square, Yod, Kite, Mystic Rect., Cradle, Talent Triangle and more.

Sources: Robert Hand "Horoscope Symbols" · Bil Tierney "Aspect Patterns" · Donna Cunningham

Placidus

Most popular time-based system — recommended for latitudes ±60°.

Koch

Placidus alternative, popular in Germany.

Whole Sign

Most ancient system: one sign = one house. Revived by Hellenists.

Equal House

Equal 30° houses from the Ascendant.

Porphyrius

Simple trisection of quadrants — ancient Greek system.

Regiomontanus

Division by celestial equator. Medieval astrology standard.

Campanus

First vertical divided into 12 equal parts.

Morinus

Latitude-independent — useful for polar locations.

Topocentric (Polich-Page)

Modern Placidus alternative — more accurate at high latitudes.

Alcabitius

Medieval Arabic time-based system — parallel to Placidus.

Meridian / Axial

Equator-based division — useful for astrolabes and asteroid researchers.

Sources: Ptolemy Tetrabiblos III · Lilly Christian Astrology · Ralph Holden "The Elements of House Division"

Jupiter–Pluto transits

Long-term life cycles and generational themes.

Mercury–Mars transits

Daily and weekly moods, tactics.

Lunar transits

Emotional rhythms, short-term peaks.

Eclipses

Solar and lunar eclipses — pivot points of 6-month cycles.

Retrograde periods

Complete retrograde calendar for all planets 1891–2099.

Stations

Moments planets stop — peak influence points.

Declinations

Parallels and contraparallels — north–south aspects.

Out-of-bounds planets

Planets beyond ±23°27' — non-standard expressions.

Mundane transits

Transits to national charts per Nick Campion — politics and world events.

Ingress charts

Charts at Sun's entry into cardinal signs — seasonal forecast.

Sources: Robert Hand "Planets in Transit" · Howard Sasportas "The Gods of Change" · Nick Campion "Book of World Horoscopes"

Secondary progressions

Day after birth = year of life. The most popular technique.

Tertiary progressions

Lunar month = year of life.

Minor progressions

Month after birth = year of life.

Solar Arc

All planets shift by the Sun's daily motion amount.

Directions

Direct and converse symbolic advancements.

Primary directions

Ptolemy's technique — directions through celestial arcs.

Progressed lunation cycle

8-phase cycle of progressed Moon and Sun.

Converse directions

Progressions into the past — analysis of karmic premises of the current phase.

Sources: Robert Blaschke "Progressions" · Bernadette Brady "Predictive Astrology"

Solar return

Sun's return — chart for the year from birthday.

Lunar return

Moon's return — chart for ~28 days.

Saturn return

~29.5 years — maturation turning points.

Jupiter return

~12 years — expansion cycles.

Venus return

~225 days — relationship cycles.

Mercury return

~88 days — communication cycles.

Demi-returns

Returns to opposition — cycle midpoints.

Demi-solar

Half-year solar return (180° from birthday) — annual cycle re-evaluation point.

Anniversary returns

Returns at 5/10/15/20/25 years — multiple-cycle anchors.

Sources: Mary Shea "Planets in Solar Returns" · Celeste Teal "Lunar Nodes & Returns"

Classical synastry

Aspects between one chart's planets and another's.

Midpoint composite

Chart of longitude midpoints — single chart of the couple.

Relational composite

Combined chart anchored to a location.

Davison chart

Chart for the midpoint of dates and birthplaces.

Destiny chart

Time-space midpoint techniques.

Relationship houses

5th, 7th, 8th — love, marriage, intimacy.

Couple's lunar phase

Moon phase in the composite sets the relationship's energy.

Parallels in synastry

Declination overlap between two charts — an invisible but powerful link.

Declination aspects

OoB planets in synastry — where the partner pulls you beyond your usual limits.

Sources: Stephen Arroyo "Relationships & Life Cycles" · Robert Hand "Planets in Composite" · John Townley

Profections

Age-based house and its lord — primary theme of the year.

Firdaria

Persian system of planetary life periods.

Zodiacal Releasing

Lots of Fortune and Spirit — career and spiritual period technique.

Time lords

Planetary rulers of periods in Hellenistic astrology.

Circumambulations

Ptolemy's circular movement through the bounds.

Profected year

Current age-sign and its ruler.

Planetary periods

Lesser, middle and greater planetary periods.

Ascensions

Ptolemy's method: each sign rises in its own time — basis of primary directions.

Prenatal syzygy

New or full moon preceding birth — karmic context of the chart.

Sources: Vettius Valens Anthology · Dorotheus Carmen Astrologicum · Chris Brennan "Hellenistic Astrology"

4 Royal Stars

Aldebaran, Regulus, Antares, Fomalhaut — Watchers of the four corners.

63 Robson stars

Classical star catalog per Vivian Robson 'Fixed Stars and Constellations' (1923).

12 Behenian

Agrippa's magical stars for talismans — 'Three Books of Occult Philosophy' II.32.

39 Brilliant Stars (Brady)

Heliacal risings per Bernadette Brady 'Brilliant Stars' (2015) — stars of birth.

25 Hellenistic

Stars from Tetrabiblos I.9 — Ptolemy's classification of planetary natures.

Parans

Stars at the angles when planets rise.

Heliacal rising

First appearance of a star after conjunction with the Sun.

Star parallels

Stars at the same declination as natal planets.

28 Lunar mansions (Western)

Agrippa II.46 and Picatrix — Arabic tradition, distinct from Vedic's 27 nakshatras.

Sources: Vivian Robson "Fixed Stars" · Bernadette Brady "Brilliant Stars" · Ptolemy Tetrabiblos I.9 · Agrippa "Three Books of Occult Philosophy" II.46 · Picatrix

Chiron

Wounded Healer — point of deep wound and gift.

Ceres

Motherhood, nurture, nourishment, cycles.

Pallas

Wisdom, strategy, pattern recognition.

Juno

Marriage, fidelity, partnership.

Vesta

Sacred flame, devotion to a calling.

Lilith

Black Moon — shadow feminine.

Eros & Psyche

Sexual attraction and soul connection.

Centaurs

Chiron, Nessus, Pholus, Chariklo — boundary bodies.

Pholus, Nessus, Chariklo

'Lesser centaurs' — toxic relationships, genetic themes, feminine wisdom.

Dark Moon (Selena)

Hypothetical Earth satellite — point of purification and karmic grace.

Sources: Demetra George "Asteroid Goddesses" (1986) · Melanie Reinhart "Chiron and the Healing Journey"

14 Arabic Lots

14 key lots implemented: of Fortune, Spirit, Love, Death, Sickness, Marriage, Children, Career and others.

Lot of Fortune

Body, health, luck — primary lot.

Lot of Spirit

Career, action, reputation.

Sect (diurnal / nocturnal)

Day or night chart determines benefic planets.

Triplicity rulers

Element rulers per Dorotheus: day / night / participating.

Ptolemy's bounds

Each sign divided into 5 unequal parts by planet.

Decans

Sign divided into 3 parts of 10° — each with its own planetary ruler.

Essential dignities

Domicile, exaltation, triplicity, bounds, face — 5-point scoring.

Antiscia

Mirror points across the Cancer–Capricorn axis.

Dodecatemoria

12-fold subdivision of each sign — Dorotheus of Sidon, micro-reading of a degree.

Monomoiriai

Single-degree analysis by Chaldean order — a ruler for each of the 360 degrees.

Decanic faces

Ruler of a 'face' (10°) — weakest essential dignity (+1 point).

Sources: Ptolemy Tetrabiblos · Dorotheus Carmen · Vettius Valens Anthology · Antiochus · Hephaistio

360 Sabian symbols

One symbol per ecliptic degree — Marc Edmund Jones (1925) + Dane Rudhyar (1973).

106 midpoints (Ebertin)

Complete Cosmobiology — each pair of planets yields a point read through a third.

Harmonics

5th, 7th, 9th harmonic charts — John Addey.

Vertex

Electric point of fated encounters.

Part of Fortune

Modern interpretation of the Hellenistic lot.

East Point / Anti-Vertex

Additional angular point of the chart.

Cosmic Cross

AC-DC and MC-IC axes as four directions of personality.

Planetary hours

Chaldean order: each hour of the day is ruled by a planet.

5 critical degrees

0°/13°/26° cardinal, 8-9°/21-22° fixed, 4°/17° mutable — peak points.

Black Moon Lilith

Lunar orbit's apogee — shadow feminine, karmic independence.

Uranian (hypothetical)

Cupido, Hades, Zeus, Kronos, Apollon, Admetos, Vulkanus, Poseidon — Hamburg School.

Sources: Marc Edmund Jones (1953) · Dane Rudhyar "An Astrological Mandala" (1973) · Reinhold Ebertin "Combination of Stellar Influences"

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