Lecture 49 — The Birth Chart

by The Editor

Contents List:

The Birth Chart
The Ascendant
The Signs of the Zodiac
The "Planets"
Planetary Aspects
Planetary Transits
Sources of Information

Return to:

Index to Hermetic System Lectures
Ardue Site Plan

See also:

Introduction to Astrology

The Birth Chart

The Birth Chart or horoscope is the indispensable tool of the astrologer's trade. It is essentially a circular diagram showing the horizontal bearings of certain heavenly bodies as seen (or unseen) from the place and time of the birth of the subject. It is, in fact, an attempt to "picture" the Ecliptic from the point of view of the place of birth at the moment of drawing the first breath, which is taken to be the commencement of life as an individual entity.

However, because astrology can be applied to things and events as well as to human beings, such a chart may be used with reference to the beginning or occurrence of anything whatever.

A blank chart normally consists of two concentric circles. The rim of the outer circle is divided into 360 degrees grouped in twelve segments each of thirty degrees.

The Ascendant

The Ascendant (AS) is the specific degree of the Zodiac that was on the eastern horizon (rising) at the moment for which the horoscope was cast (i.e., calculated, drawn, or "erected"). In other words, it is the direction of true East from the place and at the time of birth, occurrence, or commencement.

Having identified the Ascendant, the whole chart is drawn to represent the sky as it appeared at the designated time and place. The more precisely the time and place are known, the more accurate the chart.

Taking myself as example, I drew my first breath at such a time and place that my personal chart (as produced using the software included with The Instant Astrologer by Lyn Birkbeck) shows "my" Ascendant to be at 21°36' of Pisces, which may be abbreviated to (21Pi36). This point is therefore taken as the East for "my" chart. The glyph for the Sign of Pisces is placed at the edge of this 30° segment.

"My" Ascendant axis is the diameter of the circle between 21Pi36 and 21Vi36. This last point, representing the West, is called the Descendant.

"My" Chart

The Signs of the Zodiac

The glyphs for the remaining Signs of the Zodiac identify the remaining 30° segments. They appear in anticlockwise order starting with Aries (Ar) through Taurus (Ta), Gemini (Ge), Cancer (Ca), Leo (Le), Virgo (Vi), Libra (Li), Scorpio (Sc), Sagittarius (Sa), Capricorn (Cp), and Aquarius (Aq). On a Natal Chart, the Signs of the Zodiac not only represent the "field of play" for the "game of life" but also serve the indispensable function of defining directions.

The astrological year begins at the moment (usually on the 21st of March) when the Sun crosses the Equator in its transit from South to North at what in the Northern Hemisphere is called the "Vernal Equinox". The position of the Sun at this moment is called the first point of Aries, (00Ar00). As there are twelve Signs each of 30° and the Sun "visits" each of them once every year, the dates on which it enters and leaves each Sign are virtually constant. Thus the subject's birthday defines his or her Sun Sign sufficiently accurately for the rough-and-ready approach taken by astrologers in the popular press.

As well as the Horizon (or Ascendant-Descendant axis), the chart shows another diameter running almost vertically from top to bottom. The end at the top of the chart marks the position of the Sun at local Noon (midday). The line is called the Meridian and the upper end is called the MidHeaven, usually abbreviated to MC (Latin medium coeli, middle of the sky). In "my" chart, MC is at 27Sa43. The opposite end of the Meridian is IC (imum coeli) and is at 27Ca43.

The "Planets"

The Sun did not "rise and shine" upon my birthplace until the Sign of Aries had nearly half-risen on the eastern horizon. Hence "my" Sun is shown at 13Ar59 and my Sun Sign, therefore, is Aries.

The positions of the remaining "planets" are indicated by their glyphs. The "pair of headphones" at 07Pi08 is the North Lunar Node, the northerly point at which the Moon's orbit intersects the Ecliptic. It is considered important because it is the point at which eclipses occur.


Besides the annual pattern in the sky represented by the Signs of the Zodiac, there is also a daily pattern arising from the Earth's anti-clockwise rotation on its axis.

Every 24 hours, the Sun, Moon, planets, Signs of the Zodiac, and constellations of stars appear to follow a clockwise path through the sky, rising in the East and setting in the West. Charting this pattern on the horoscope with reference to the Ascendant enables us to tell at any time in what part of the sky all the heavenly bodies are to be found. This is facilitated by dividing the chart into another twelve segments called houses taking the Ascendant as the beginning of the First House and proceeding anticlockwise to the end of the Twelfth House.

Different astrologers use different House systems, making some Houses "wider" than others. At this point on my learning curve, I have no very clear idea what the differences imply. On "my" specimen chart, the house numbers are shown around the circumference of the inner circle. Because the chart was drawn up using the 'Placidus' system, the First, Sixth, Seventh, and Twelfth Houses are much wider than the others, whereas the Third, Fourth, Ninth, and Tenth Houses are allocated the smallest "slices of the cake".

"My" First House (or first segment of sky) contains the Sun, Mercury, Venus, and Uranus, Mercury being "retrograde" (apparently travelling "backwards") and very close to the ascendant. The Moon and a retrograde Pluto are in my Fifth House; Mars, Jupiter, and Neptune (all retrograde) are in my Sixth House; and Saturn is in my Twelfth House. The Meridian marks the division between the Third and Fourth, and between the Ninth and Tenth Houses.

I am already beginning to form a personal preference for the "equal house" system in which all Houses are the same size on the chart. The Earth rotates at a steady rate and so the heavenly bodies actually move through an arc of thirty degrees every two hours irrespective of whether I was born on the Equator or on the Arctic Circle.

On an "equal house" chart, "my" Uranus would be just beyond the cusp of the Second House, so another astrologer might interpret "my" chart somewhat differently — pointing the moral that Astrology is at least as much an art as a science.

Planetary Aspects

Aspects indicate the angular relationships on the chart between pairs of planets at any given time, and aspects thought to be "significant" are drawn inside the inner circle.

I am attracted to the "harmonic" system of classification of aspects, the theory of which goes back at least as far as Pythagoras of Samos and is derived from dividing the 360 degrees of the circle by small whole numbers to give, successively, 360°, 180°, 120°, 90°, 72°, 60°, 51°, 45°, etc. (The Signs and Houses are based on division by 12). For me, this approach "chimes" with the "Music of the Spheres", a musical analogy for the psychological or archetypal influences of the heavenly bodies.

When two planets are in the same position or very close together on the chart, they are said to be conjunct or in conjunction, representing harmonic union or perfect togetherness. The other aspects thought to be significant are, in order, opposition (180°), trine (120°), square (90°), and sextile (30°).

Inter-relationships among three or more planets can get quite complicated.

Planetary Transits

As the planets move around (transit) the Ecliptic at different rates, they are continually changing their angular relationships with one another and therefore the aspects between themselves and other significant constituents of the chart. These changes in angular relationships produce subtle variations in their combined "harmony" and therefore in their conscious or unconscious influences on the sensitive psyche.

The Sun, Moon, and inner planets all change position quite rapidly with respect to Earth, so their transits are frequent and their effects short-lived. The further out the planet, the less frequent the transits in which it is involved and the longer-lasting its effects. Therefore outer planet transits are most significant with respect to their psychic influence on national and world populations.

Planetary positions past, present, and future, have been calculated from astronomical observations and published in tables known as ephemerides. The relevant data may nowadays be held on computer, thus greatly easing the task of casting a horoscope for any time and place. This includes identifying and predicting the occurrence of potentially significant aspects.

In his Introduction to Planets in Transit, Robert Hand writes:
"The study of transits is one of the most fundamental techniques in astrology. That transits indicate important trends and issues in your life is one of the few points upon which all astrologers agree."

Later, he says:
"The purpose of astrology really should be to give you an understanding of your place in the Universe and the kinds of energies that are flowing through you and through the physical universe. Astrology should not try to make up your mind but instead provide information upon which you can make an intelligent decision. Obviously, transits indicate times that are appropriate for certain kinds of actions and inappropriate for others, and certain kinds of events often do occur with particular transits. But transits should never be viewed as signifying events that will inevitably come to pass, with you as a helpless observer."

Robert's book gives a comprehensive account of the likely effects on your psyche when a particular planet transits each house in your chart or forms a significant aspect with another planet, your Ascendant, your MidHeaven, or the position the planet occupied in your Birth Chart. A conjunction of a planet with its position on the Natal Chart marks a new cycle for that planet.


When I was young and intellectually too arrogant for my own good, I was probably more sceptical than most people about the value of astrology. However, during a long and reasonably varied life, I have learned not to prejudge the value of anything until I have tried it for myself, and I can now say that, having had my chart drawn up and interpreted by various experts and tested by myself, I have learned a great deal about my own relationship with the Universe that I might not have learned in any other way.

In particular, I have come to form the opinion that the study of planetary transits is of great potential value as an aid in decision-making, not only for the "ordinary" individual but more importantly for politicians, for statesmen, for journalists, for educators, and for movers and shakers in economic matters.

However, I don't expect anyone to take my word for it. If you are an interested doubter, have your personal horoscope drawn up and charted, and test various interpretations for yourself. All you need to start with is the time and place of your birth as accurately as possible — ideally to the nearest minute of time, latitude, and longitude.

Sources of Information

Information and help for "starters" may be obtained from books (which may be borrowed from libraries), computer software, and the Internet.

Among the books I have used are:

For drawing charts and calculating transits, I can recommend:

Useful sites on the Internet include:

As you "get up to speed", you might like to:

Whatever you do, I hope you enjoy your studies!