Glossary of Astrological Terms #

This glossary explains astrological concepts used in Kerykeion, designed for developers who may be new to astrology.

Chart Components #

Natal Chart (Birth Chart) #

A map of the sky at the exact moment and location of birth. Shows the positions of celestial bodies in the zodiac signs and houses.

In Kerykeion:

chart_data = ChartDataFactory.create_natal_chart_data(subject)

Zodiac #

The 12-sign system used to divide the ecliptic (the Sun’s apparent path). Each sign spans 30°.

Types:

• Tropical (default): Based on the seasons. 0° Aries = spring equinox.
• Sidereal: Based on fixed stars. Used in Vedic astrology.

Houses #

The 12 divisions of the chart representing different life areas. Unlike signs (which are celestial), houses are based on the observer’s location on Earth.

Ascendant (Rising Sign) #

The zodiac sign rising on the eastern horizon at the time of birth. Determines the 1st house cusp and is one of the most important chart points.

In Kerykeion:

print(subject.first_house.sign)  # The Ascendant sign
print(subject.ascendant.position)  # Exact degree

Midheaven (MC - Medium Coeli) #

The highest point in the chart, representing career and public image. The cusp of the 10th house in most house systems.

In Kerykeion:

print(subject.tenth_house.sign)
print(subject.medium_coeli.position)

Descendant (DC) #

The point opposite the Ascendant, representing partnerships. The cusp of the 7th house.

Imum Coeli (IC) #

The lowest point in the chart, opposite the MC. Represents home and roots. The cusp of the 4th house.

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Celestial Bodies #

Planets #

In astrology, “planets” includes the Sun and Moon (called “luminaries”), plus Mercury through Pluto.

Lunar Nodes #

The points where the Moon’s orbit crosses the ecliptic. Related to karmic themes.

• North Node (Rahu): Future direction, growth
• South Node (Ketu): Past patterns, comfort zone

In Kerykeion:

# True nodes (oscillating)
print(subject.true_north_lunar_node)
print(subject.true_south_lunar_node)

# Mean nodes (averaged)
print(subject.mean_north_lunar_node)
print(subject.mean_south_lunar_node)

Chiron #

A “centaur” asteroid representing wounds and healing.

Lilith (Black Moon) #

The lunar apogee, associated with shadow self and repressed desires.

• Mean Lilith: Averaged position
• True Lilith: Oscillating position

Asteroids #

Minor bodies in the asteroid belt:

• Ceres: Nurturing, agriculture
• Pallas: Wisdom, strategy
• Juno: Partnerships, commitment
• Vesta: Focus, dedication

Arabic Parts (Lots) #

Calculated points based on formulas involving other chart positions:

• Part of Fortune (Pars Fortunae): Luck, prosperity
• Part of Spirit (Pars Spiritus): Soul purpose

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Aspects #

Angular relationships between planets that create energetic connections.

Major Aspects #

Minor Aspects #

Orb #

The tolerance in degrees for an aspect to be considered active. A conjunction with 8° orb means planets within 8° of each other are “in conjunction.”

In Kerykeion:

# Aspect data includes orb
aspect.orbit  # The actual deviation from exact

Applying vs Separating #

• Applying: Planets moving toward exact aspect (considered stronger)
• Separating: Planets moving away from exact aspect

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Dignities & Debilities #

Domicile (Rulership) #

A planet in the sign it rules. The planet operates at full strength. For example, Mars in Aries or Venus in Taurus.

Exaltation #

A planet in the sign where it is considered especially powerful (though not its ruler). For example, the Sun is exalted in Aries, the Moon in Taurus.

Detriment #

A planet in the sign opposite its domicile. Considered weakened or challenged. For example, Mars in Libra (opposite Aries).

Fall #

A planet in the sign opposite its exaltation. Considered at its weakest dignity. For example, the Sun in fall in Libra (opposite Aries).

Peregrine #

A planet with no essential dignity in its current sign — not in domicile, exaltation, triplicity, term, or face. Sometimes described as “wandering.”

Decanate (Decan) #

Each zodiac sign is divided into three 10° segments called decanates (or decans). The first decan spans 0°-10°, the second 10°-20°, the third 20°-30°. Each decan has its own sub-ruler, adding nuance to interpretation.

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Technical Terms #

Ayanamsa #

The angular difference between tropical and sidereal zodiacs. Different ayanamsas (like Lahiri or Fagan-Bradley) define different starting points.

Retrograde #

When a planet appears to move backward through the zodiac due to relative orbital positions. Significant in interpretation.

In Kerykeion:

if subject.mercury.retrograde:
    print("Mercury is retrograde")

Declination #

A planet’s angular distance north or south of the celestial equator. Planets with the same declination are “in parallel.”

Ephemeris #

Tables showing planetary positions for each day. Kerykeion uses the Swiss Ephemeris for high-precision calculations.

Julian Day #

A continuous count of days since January 1, 4713 BCE. Used internally for astronomical calculations.

In Kerykeion:

print(subject.julian_day)

Void-of-Course Moon #

The period after the Moon makes its last major aspect in a sign and before it enters the next sign. Traditionally considered an unfavorable time for initiating new actions. Duration varies from minutes to over a day.

Note: Kerykeion does not calculate void-of-course periods directly, but you can determine them by analyzing Moon aspects and sign ingresses using EphemerisDataFactory and AspectsFactory.

Progressed Chart #

A forecasting technique where each day after birth corresponds to one year of life (secondary progressions). For example, the planetary positions 30 days after birth represent the progressed chart for age 30.

Note: Kerykeion does not currently implement progressions. For progressed charts, calculate the date offset manually and create an AstrologicalSubjectFactory for that date.

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Chart Types #

Synastry Chart #

Overlays two natal charts to analyze relationship compatibility. Shows how one person’s planets aspect the other’s.

synastry_data = ChartDataFactory.create_synastry_chart_data(person1, person2)

Composite Chart #

Creates a single chart from the midpoints of two people’s charts. Represents the relationship itself as an entity.

composite = CompositeSubjectFactory(person1, person2).get_midpoint_composite_subject_model()

Transit Chart #

Compares current planetary positions to a natal chart. Used for timing and prediction.

transit_data = ChartDataFactory.create_transit_chart_data(natal_subject, transit_subject)

Solar Return Chart #

The chart for the moment the Sun returns to its exact natal position each year. Used for annual forecasts.

return_subject = PlanetaryReturnFactory(natal, ...).next_return_from_date(2024, 1, 1, return_type="Solar")

Lunar Return Chart #

The chart for the Moon returning to its natal position (approximately monthly).

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Elements & Qualities #

Elements (Triplicities) #

The four classical elements each ruling three signs:

Qualities (Modalities) #

Three modes describing how signs express energy:

In Kerykeion:

print(chart_data.element_distribution.fire_percentage)
print(chart_data.quality_distribution.cardinal_percentage)

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Lunar Phases #

In Kerykeion:

print(subject.lunar_phase.moon_phase_name)
print(subject.lunar_phase.moon_emoji)

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House Systems #

Different methods for calculating house cusps:

See House Systems for the complete list.

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