CTSA™ Study Guide
This is the study guide for the CTSA written exam in true sidereal astrology. Everything the exam can test is taught in this one document. Read it start to finish before your exam. Come back to the tables whenever you need a quick refresher.
About the exam
The exam is the same whether you come through the course or the CTSA professional path.
The written exam is 60 questions and 90 minutes, closed-book and monitored. There are three sections: 10 fill-in-the-blank, 20 short answers, and two charts to read (one natal and one transit) with 15 short-answer questions each. You pass at 90%. Periodic webcam photos are captured through the exam page for integrity review and deleted once your result is released.
You take the exam on a desktop computer using Chrome, Edge, Firefox, or Safari, with a working webcam. Your exam fee includes two attempts. There is a 48-hour wait between attempts, and you have a full year to use them.
How it is graded
We grade the idea, not the wording. Facts are marked against set answers with reasonable variants accepted (for example, both "quincunx" and "inconjunct" count). Short answers pass as long as the right idea comes through. Chart questions ask you to either identify something and/or interpret it.
The zodiac systems
Three main zodiac systems are in use today. Know what each one is anchored to.
Tropical zodiac: anchored to the seasons. Its 0° Aries always begins at the spring equinox. Because the sky and the seasons no longer line up, the tropical signs no longer sit over the actual constellations they are named for. This is the most popular Western system.
Sidereal zodiac: anchored to the fixed stars, but divided into 12 equal 30° signs. Vedic and Western sidereal astrology uses this form.
True sidereal zodiac: anchored to the actual constellations, with signs of unequal length, and 13 signs including Ophiuchus. Uses the true sizes of the constellations as they appear in the sky.
Precession and the ayanamsa
The tropical and sidereal zodiacs drift apart because of an astronomical phenomenon called the precession of the equinoxes. Earth's axis wobbles in a slow circle that takes about 26,000 years to complete. This wobble causes the spring equinox point to slowly shift backward through the constellations at a rate of roughly one degree every 72 years. The current offset between the tropical and sidereal zodiacs is about 24 degrees.
That offset has a name: the ayanamsa. It marks how far the sidereal zodiac begins from the tropical zodiac. Different sidereal systems use different ayanamsa values (Lahiri, Fagan-Bradley, and others), which is why sign dates vary slightly between them.
Ophiuchus and the thirteenth sign
True sidereal recognizes 13 signs because the Sun actually passes through 13 constellations along the ecliptic (the Sun's apparent yearly path across the sky). The 13th is Ophiuchus, the Serpent Bearer, which passes through the ecliptic between Scorpio and Sagittarius and shares the same part of the sky as Scorpio.
In the true sidereal zodiac, the signs are unequal in length because the constellations themselves are different sizes. The Sun spends the longest time in Virgo, which is a very large constellation.
The signs
Signs describe how an energy is expressed. Know the element, modality, ruler, and core qualities of every sign.
| Sign | Element | Modality |
|---|---|---|
| Aries | Fire | Cardinal |
| Taurus | Earth | Fixed |
| Gemini | Air | Mutable |
| Cancer | Water | Cardinal |
| Leo | Fire | Fixed |
| Virgo | Earth | Mutable |
| Libra | Air | Cardinal |
| Scorpio | Water | Fixed |
| Ophiuchus | Water | Fixed |
| Sagittarius | Fire | Mutable |
| Capricorn | Earth | Cardinal |
| Aquarius | Air | Fixed |
| Pisces | Water | Mutable |
The elements
| Element | Character |
|---|---|
| Fire | Passion, action, spirit, drive |
| Earth | Practicality, form, grounding, material |
| Air | Ideas, communication, connection, exchange |
| Water | Feeling, emotion, depth, flow |
The modalities
| Modality | Character |
|---|---|
| Cardinal | Initiating, active, starts new cycles |
| Fixed | Stabilizing, sustaining, holds form |
| Mutable | Adapting, transitioning, flexible |
Core qualities of each sign
| Sign | Core qualities |
|---|---|
| Aries | self-aware, assertive, pioneering, direct, courageous, initiating |
| Taurus | grounded, sensual, resourceful, patient, values comfort and stability |
| Gemini | curious, communicative, versatile, quick-thinking, sociable |
| Cancer | nurturing, protective, emotional, sensitive, home and family oriented |
| Leo | creative, self-expressive, warm, playful, loves to shine and be seen |
| Virgo | analytical, precise, service-oriented, improving, refining, practical |
| Libra | fair, harmonizing, cooperative, relationship-focused, aesthetic |
| Scorpio | intense, private, transformative, penetrating, passionate |
| Ophiuchus | healing, regenerative, transmuting, redemptive |
| Sagittarius | adventurous, philosophical, freedom-loving, optimistic, expansive |
| Capricorn | ambitious, disciplined, responsible, structured, achievement-oriented |
| Aquarius | inventive, humanitarian, unconventional, visionary, community-minded |
| Pisces | imaginative, compassionate, dreamy, intuitive, spiritual, receptive |
The planets
Know the core meaning of each planet. The Sun and Moon are the core outer and inner consciousness. Mercury, Venus, and Mars are the personal planets. Jupiter and Saturn are the societal planets that structure our growth and maturity. Uranus, Neptune, and Pluto are the outer, generational planets that shape long-range transformation. The North and South Nodes are not planets, but they carry deep meaning about our life direction.
| Planet | Core meaning |
|---|---|
| Sun | Core self, identity, vitality, will, where you shine. |
| Moon | Emotions, feelings, instincts, needs, nurturing, what makes you feel secure. |
| Mercury | Mind, communication, thinking, learning, curiosity, processing information. |
| Venus | Love, values, attraction, beauty, pleasure, what you are drawn to. |
| Mars | Drive, action, desire, assertion, how you go after what you want. |
| Jupiter | Expansion, growth, optimism, opportunity, faith, philosophy, abundance. |
| Saturn | Structure, discipline, responsibility, limits, maturity, hard work over time. |
| Uranus | Freedom, sudden change, revolution, individuality, breaking from the norm. |
| Neptune | Dreams, imagination, spirituality, compassion, dissolution, transcendence. |
| Pluto | Transformation, power, depth, death and rebirth, hidden intensity. |
| North Node | Growth, learning, conscious orientation toward destiny. |
| South Node | Familiarity, karmic comfort zone, what to release. |
Benefics and malefics
In traditional astrology, planets are grouped by their general tone. No planet is purely good or bad, but the classification names the natural leanings of each.
| Category | Planets | Tone |
|---|---|---|
| Benefics | Venus (lesser), Jupiter (greater) | Bring ease |
| Malefics | Mars (lesser), Saturn (greater) | Bring challenge |
| Neutral | Mercury | Variable |
Rulership
Each sign has a ruling planet. The ruler tells you where and how that sign's affairs express: to read a sign or a house, look at its ruler's placement.
| Sign | Ruler |
|---|---|
| Aries | Mars |
| Taurus | Venus |
| Gemini | Mercury |
| Cancer | Moon |
| Leo | Sun |
| Virgo | Mercury |
| Libra | Venus |
| Scorpio | Mars |
| Ophiuchus | Mars |
| Sagittarius | Jupiter |
| Capricorn | Saturn |
| Aquarius | Saturn |
| Pisces | Jupiter |
The rulers above are the traditional rulers. In modern rulership, Scorpio is ruled by Pluto, Aquarius by Uranus, and Pisces by Neptune. Either traditional or modern rulers are accepted on the exam.
The chart ruler is the planet that rules the sign on the 1st house cusp (the sign of the Ascendant). It is a key significator of the whole chart. Its sign, house, and aspects color the person's overall direction and life energy.
The essential dignities
A planet expresses strongly in two kinds of sign (its domicile and its exaltation) and weakly in the two opposite signs (detriment and fall).
Domicile is the sign a planet rules (see the rulers table above).
Exaltation is a separate sign of special strength.
| Planet | Exalted in |
|---|---|
| Sun | Aries |
| Moon | Taurus |
| Mercury | Virgo |
| Venus | Pisces |
| Mars | Capricorn |
| Jupiter | Cancer |
| Saturn | Libra |
Detriment is the sign opposite a planet's domicile. (The Sun rules Leo, so it is in detriment in Aquarius.)
Fall is the sign opposite a planet's exaltation. (The Sun is exalted in Aries, so it is in fall in Libra.)
The houses
Houses are the areas of life, or where an energy plays out. They are numbered counterclockwise from the Ascendant.
| House | Area of life |
|---|---|
| 1st | Self, identity, appearance, new beginnings, how you come across. |
| 2nd | Money, possessions, values, self-worth, personal resources, talents. |
| 3rd | Communication, siblings, immediate environment, short trips, learning. |
| 4th | Home, family, roots, emotional foundations, private life. |
| 5th | Creativity, self-expression, romance, children, play, hobbies. |
| 6th | Work, daily routines, health, service, habits, skills. |
| 7th | Committed partnerships, one-on-one relationships, open enemies, agreements. |
| 8th | Shared resources, transformation, intimacy, death and rebirth, the hidden. |
| 9th | Higher learning, philosophy, long-distance travel, foreign cultures, meaning. |
| 10th | Career, public life, reputation, achievement, authority, social standing. |
| 11th | Friends, groups, community, hopes and goals, the collective. |
| 12th | Unconscious, solitude, spirituality, hidden things, endings, institutions. |
The four angles
Four angles anchor the chart to the sky at the moment of birth.
| Angle | Position | Represents |
|---|---|---|
| Ascendant (AC) | Eastern horizon, cusp of 1st house | The rising sign. What life is guiding you to develop. |
| Descendant (DC) | Western horizon, opposite the Ascendant | What you meet in others. |
| Midheaven (MC) | Where the ecliptic meets the meridian, top of the chart | Your public role and direction. |
| Imum Coeli (IC) | Opposite the MC, bottom of the chart | Your roots, your past, and where you feel anchored. |
Angular, succedent, and cadent houses
The 12 houses group into three sets of four, matching the sign modalities.
| Group | Houses | Character |
|---|---|---|
| Angular (Cardinal) | 1, 4, 7, 10 | Most active and initiating. Planets here strongly shape the life. |
| Succedent (Fixed) | 2, 5, 8, 11 | Consolidating and stabilizing what the angular houses initiate. |
| Cadent (Mutable) | 3, 6, 9, 12 | Adapting, learning, transitioning, preparing for the next angular house. |
The hemispheres
When planets cluster in a hemisphere, that hemisphere's themes stand out in the chart.
| Hemisphere | Houses | Emphasis |
|---|---|---|
| Upper half | 7 through 12 (above the horizon) | Public, outer, and visible areas of life. |
| Lower half | 1 through 6 (below the horizon) | Personal, private, and inner areas of life. |
| Eastern half | 10 through 3 (contains the Ascendant) | Self-determination, autonomy, and free will. |
| Western half | 4 through 9 (contains the Descendant) | Interaction with others and adapting to the world. |
Aspects
Aspects are the geometric relationships between planets, measured in degrees along the zodiac. They describe how the planets' energies interact.
| Aspect | Degrees | What it does |
|---|---|---|
| Conjunction | 0° | Blend, fusion, intensification. Energies merge and act as one. |
| Semi-sextile | 30° | Subtle, minor connection. Small adjustments between two energies. |
| Sextile | 60° | Supportive opportunity. Harmony that becomes real once you act on it. |
| Square | 90° | Tension and friction. Dynamic pressure that motivates growth. |
| Trine | 120° | Ease and flow. Natural harmony and innate talent. |
| Quincunx | 150° | Awkward adjustment. Two energies that do not naturally fit; growth through working with the friction. |
| Opposition | 180° | Polarity. Two opposing pulls that need balancing, often experienced through other people. |
An applying aspect is still forming: the faster planet is moving toward the exact degree. Applying aspects are building, gaining strength, and tend to be more difficult. A separating aspect has already passed exact, is moving apart, and tends to be easier to work with.
A stellium is a cluster of three or more planets grouped together in one sign or one house. It concentrates and intensifies the themes of that sign or house.
Planetary cycles
Every planet has a cycle: how long it takes to return to a given place in the zodiac.
| Planet | Return |
|---|---|
| Moon | ~27 days |
| Sun | ~1 year |
| Mercury | ~1 year |
| Venus | ~1 year |
| Mars | ~2 years |
| Jupiter | ~12 years |
| Saturn | ~29 years |
| Uranus | ~84 years |
| Neptune | ~165 years |
| Pluto | ~248 years |
| Lunar nodes | ~19 years |
To find how long a planet spends in one sign, divide its return by 12. So Jupiter (12 years) spends about 1 year per sign, Saturn (29) about 2.5 years, and Uranus (84) about 7 years.
Planets also form cycles with each other. Jupiter and Saturn, for example, come together every 20 years.
Retrograde motion
Retrograde is when a planet appears to move backward through the zodiac as seen from Earth. It is an apparent optical effect caused by the relative orbital speeds of Earth and the planet, not an actual reversal in the planet's orbit. The Sun and Moon never go retrograde.
| Planet | Retrograde frequency |
|---|---|
| Mercury | ~3 to 4 times a year |
| Venus | ~1.5 years |
| Mars | ~2 years |
| Jupiter through Pluto | ~1 year |
In a natal chart, a retrograde planet's energy is turned inward, internalized, or reworking.
In transits, an outer planet makes one, three, or five exact contacts to a natal point: the first brings the initial impact, the middle (during retrograde) brings insight and understanding, and the last brings integration and final resolution. Single contact transits integrate all three phases at once.
The lunar nodes and eclipses
Astronomically, the lunar nodes are the two points where the Moon's orbit crosses the ecliptic. The North Node is where it crosses going up; the South Node is where it crosses going down. Eclipses can only occur when a New or Full Moon falls close to one of the nodes. An eclipse falling in a natal house tends to signal a new beginning or a major shift in that area of life.
Progressions
A secondary progression is a symbolic method of prediction that maps one day after birth to one year of life. Progressions primarily describe long-term psychological and emotional themes rather than specific external events with fixed dates.
| Progressed body | Movement |
|---|---|
| Progressed Sun | About 1° per year. About 30 years in each sign or house. |
| Progressed Moon | About 2.5 years per sign or house. Full cycle about 29 years. |
The progressed Sun shows the person's core focus, identity, and life direction through its current sign and house. The progressed Moon shows the person's emotional tone and inner focus.
The progressed lunar cycle
The progressed Moon moves much faster than the progressed Sun, so the angle between them changes through time. That angle defines the current phase: the cycle starts at conjunction (New Moon), waxes to opposition (Full Moon), then wanes back to the next conjunction. The full cycle takes about 29 years.
| Phase | Sun-Moon aspect | Meaning |
|---|---|---|
| New Moon | Conjunction | New beginnings. Planting seeds. Instinctive and emergent. |
| Crescent | First sextile | Movement from the new. Cultivating the new cycle. |
| First Quarter | First square | Action, obstacles, building. Construction of the new moon. |
| Gibbous | First trine | Refinement, adjustment, preparing for culmination. |
| Full Moon | Opposition | Culmination, awareness, results, high point. New directions. |
| Disseminating | Last trine | Sharing, re-adjusting, implementing what has been gained. |
| Last Quarter | Last square | Action, integration, prolonging. Construction of the full moon. |
| Balsamic | Last sextile | Release, endings, rest, preparation for the next cycle. |
Transits
Transits are the planets' current positions in the sky. They shape a chart reading in two ways: by their current house position (activating a life area) and by the aspects they form to natal points (activating those natal placements). Transits generally produce the strongest external events, while progressions produce more inner shifts.
Transit house position
As a transiting planet moves through a house, it activates that house's themes for the length of its stay. For example, transiting Jupiter in the 10th house activates career and public matters during that year.
Jupiter and Saturn activate the general themes for the year. Jupiter brings expansion, growth, opportunity, and optimism, sometimes with excess. Saturn brings testing, structure, maturation, and consolidation, sometimes with restriction.
Transiting aspects to natal points
When a transiting planet forms an aspect to a natal placement, it activates that natal placement.
Prioritize by planetary weight: outer planets (Uranus, Neptune, Pluto) to natal personal planets carry the most weight. Jupiter and Saturn set the theme. Inner planet transits (Sun, Moon, Mercury, Venus, Mars) are quicker and shorter, so they trigger the larger themes at specific times.
Confluence
When multiple transits and progressions activate the same themes at the same time, that is called confluence. Confluence signals the major themes for the year and increases the probability that a specific event might occur.
For prediction
For a predictive reading, work from the widest view inward. Look at progressions first (the progressed Sun and Moon, and the progressed lunar phase). Then Jupiter and Saturn transits. Then the finer detail: aspects from Uranus, Neptune, and Pluto to personal planets or angles, and any tight applying aspects that will go exact in the next 12 months.
Reading a chart
Start with the Sun, Moon, Ascendant, and chart ruler. These are the pillars of who the person is.
Then read the aspects, especially aspects to the Sun, Moon, Ascendant, chart ruler, and conjunctions.
Then bring it all together into a coherent picture. Look for repeated themes.
For any area of life the client asks about, read the house that governs it, the planets and signs in that house, then the rulers of that house.
Working with clients
Ethics and professional conduct make up about 5 questions of the exam. The CTSA Code of Ethics is the source of all ethics questions on the exam.
The practice exam
You also have a Practice Exam. It works just like the real one. The chart questions match the exam but with different practice charts, so you get to rehearse the real thing.