In astrology, there is a procedure known as rectification. It involves conducting a reverse analysis based on all the events in a person’s life, their character, and habits. This is entirely logical—if an astrologer can determine a person’s future and past events from their birth date, then in reverse order it is also possible to refine the exact time of birth.
To compile a horoscope independently, one still needs specialized knowledge, without which accurate results cannot be obtained. There are several methods of constructing a horoscope. The first and simplest method is to use various internet services. A large number of different programs exist that allow one to generate a natal chart. However, this option does not guarantee precise results, since the human factor plays a crucial role in this work.
The next option is compiling the natal chart manually. Generally, the methodology involves the following steps. The positions of various planets, the Sun, and the Moon for a specific time period are calculated. To determine coordinates on the plane, the ecliptic longitude of each celestial body is computed. The ecliptic in a horoscope is a circle divided into 12 sectors of 30 degrees each, corresponding to the zodiac signs. Based on ecliptic longitude, it is determined in which sector each celestial body falls. For example, if the Moon at the moment of birth was at 45 degrees of ecliptic longitude, this means that at that time the Moon was in Aquarius. The positions of other bodies are calculated in the same way.
The next step is calculating the angular distances between planets and stars. If the distance corresponds to one of the astrological aspects, it can be said that the planets and stars are in aspect to each other. In a horoscope, planets in aspect are connected by straight lines.
We have discussed the geographical location of the birthplace—it will be important at the stage of constructing the celestial sphere’s characteristics for a specific locality. It is necessary to calculate several intersection points with the horizon: the Ascendant, Descendant, and the points where the meridian intersects with the Midheaven and the Nadir. All these data are entered into a cosmogram, which represents a complete picture of the positions of celestial bodies at the moment of birth. It can be confidently stated that at this stage, the construction of the horoscope is complete.
As seen, this is a very meticulous task requiring significant time and effort. Specialized knowledge is essential to freely navigate the calculation of these values and their subsequent interpretation. Therefore, compiling a horoscope for free and without specialized knowledge presents considerable difficulty for many people.
Constructing a horoscope using ephemeris tables
But how can one construct a horoscope without specialized knowledge? There is another option—using ephemeris tables. For this, you will need a world atlas, a table of Houses, ephemeris tables, and a calculator.
Ephemerides are special tables indicating the relative positions of planets for each day. Essentially, all calculations have already been done for you. The most common tables are the "Rosenkreuzer Tables," which cover the entire 20th century. Ephemeris tables can be found in specialized publications.
House tables are needed to determine the horoscope axes and house cusps. Such tables are widely available on the Internet; among the best are the Placidus tables.
An atlas is necessary for determining the precise geographical coordinates of the birth location. Although nowadays one can also use online resources such as Google Earth, which provides the most accurate information. A calculator will be needed to perform the calculations specified in the ephemeris tables.
