Sky Basics: Astronomy for Astrologers
The celestial sphere, the ecliptic, the Moon's cycle and how a chart is calculated.
Course names, family names and outlines are shown in English. Lessons use English when a published translation is unavailable; the lesson shows a notice when this happens.
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Level 1Units: 6
Level 1 · Unit 1
The sky from Earth
The celestial sphere, the ecliptic, equinoxes and solstices, and why signs are not the same as constellations.
- The celestial sphere
- The ecliptic
- Equinoxes and solstices
- Signs vs constellations
- Checkpoint: the sky from Earth
Level 1 · Unit 2
Moon, planets and time
Moon phases, nodes and eclipses, retrograde motion, precession, and why birth time and place matter.
- Moon phases
- Nodes and eclipses
- Retrograde motion
- Precession, time and place
- Checkpoint: Moon, planets and time
Level 1 · Unit 3
Retrograde, zodiacs and precession
Inferior and superior conjunctions, opposition and synodic cycles, precession in depth, and choosing an ayanamsa for the sidereal zodiac.
- Inner planets: two conjunctions
- Outer planets: opposition and synodic cycles
- Precession in depth
- Tropical, sidereal and ayanamsas
- Checkpoint: retrograde, zodiacs and precession
Level 1 · Unit 4
The Moon in depth
Sidereal and synodic months, the eight phases measured by the Sun–Moon angle, when the Moon rises, and why its speed and distance change.
- Two kinds of month
- Eight phases by angle
- When the Moon rises
- Perigee, apogee and lunar speed
- Checkpoint: the Moon in depth
Level 1 · Unit 5
Eclipses in depth
Total, annular, partial and hybrid solar eclipses, three kinds of lunar eclipse, eclipse seasons and the eclipse year, and the 18-year saros cycle.
- Kinds of solar eclipse
- Kinds of lunar eclipse
- Eclipse seasons
- The saros cycle
- Checkpoint: eclipses in depth
Level 1 · Unit 6
Measuring the sky
Degrees and arcminutes, 0°–360° longitude, ecliptic latitude, right ascension and declination, and how astrologers use declination.
- Degrees, minutes and longitude
- Ecliptic latitude
- Right ascension and declination
- Declination in astrology
- Checkpoint: measuring the sky
Level 2Units: 6
Level 2 · Unit 1
Time for astrologers
Earth's rotation as a clock, local mean time, time zones and daylight saving, UTC, and the sidereal day.
- Earth's clock: 15° per hour
- Time zones and daylight saving
- UTC: one clock for the chart
- Sidereal time and small errors
- Checkpoint: time for astrologers
Level 2 · Unit 2
Place and the horizon
Latitude and longitude, horizon, zenith and meridian, the four angles, and why signs rise at different speeds.
- Latitude and longitude
- Horizon, zenith and meridian
- The four angles
- Fast and slow signs
- Checkpoint: place and the horizon
Level 2 · Unit 3
Ephemerides and software
Reading ephemerides, geocentric positions, how software turns birth data into a chart, and why programs can differ.
- What an ephemeris is
- Reading an ephemeris line
- From birth data to chart
- Nodes, settings and small differences
- Checkpoint: ephemerides and software
Level 2 · Unit 4
Why birth time matters
How fast each chart factor changes, where recorded birth times come from, charts with no birth time, and the idea of rectification.
- How fast each factor moves
- Where birth times come from
- Charts without a birth time
- Time windows and rectification
- Checkpoint: why birth time matters
Level 2 · Unit 5
Ephemeris skills
Spotting stations, timing sign ingresses and exact aspects by interpolation, and the extra tables many ephemerides include.
- Stations in the table
- Timing a sign ingress
- Timing an exact aspect
- Beyond the daily lines
- Checkpoint: ephemeris skills
Level 2 · Unit 6
Calendars and historical charts
Julian and Gregorian calendars, Old Style and New Style dates, local mean time in old records, year numbering and Julian Day numbers.
- Julian and Gregorian calendars
- Old Style and New Style dates
- Local mean time in old records
- Year zero and Julian Days
- Checkpoint: calendars and historical charts