Frequently asked questions

The Composite Chart is calculated from two natal charts and is supposed to give information on the nature of the relationship between two poeple. Each planet in the composite chart is on the midpoint between its positions in the two natal charts. E.g. the composite Sun takes its position in the zodiac exactly between the two natal Suns, the composite Moon is exactly in the middle between the two natal Moons, etc.

Unlike in a real natal chart, it is possible that composite Venus or Mercury are in opposition to the Sun or each other. Some drawing styles move the planet by 180° in such cases, so that it is close to the Sun.

There are two different calculation methods for the Ascendant, MC and the houses:

• "Midpoint method": All axes and houses are calculated in the same way as the planets: as composite points.
• "Reference place method": First, the composite MC is calculated in the same way as the composite planets. Then, from this MC the Ascendant and houses are calculated for the geographical latitude of the set reference place. It is recommended to use a place as reference place at which the connection between the two people "happens". It can be set in the "Extended Chart Selection" under "Default settings."

The Composite Chart is calculated from two natal charts and is supposed to give information on the nature of the relationship between two poeple. Each planet in the composite chart is on the midpoint between its positions in the two natal charts. E.g. the composite Sun takes its position in the zodiac exactly between the two natal Suns, the composite Moon is exactly in the middle between the two natal Moons, etc.

Unlike in a real natal chart, it is possible that composite Venus or Mercury are in opposition to the Sun or each other. Some drawing styles move the planet by 180° in such cases, so that it is close to the Sun.

There are two different calculation methods for the Ascendant, MC and the houses:

• "Midpoint method": All axes and houses are calculated in the same way as the planets: as composite points.
• "Reference place method": First, the composite MC is calculated in the same way as the composite planets. Then, from this MC the Ascendant and houses are calculated for the geographical latitude of the set reference place. It is recommended to use a place as reference place at which the connection between the two people "happens". It can be set in the "Extended Chart Selection" under "Default settings."

The Davison Relationship Chart is a horoscope for the midpoint of two people's birth times.

There are the following variants of the Davison Relationship Chart (DRC):

• "Davison Relationship Chart, uncorrected": The chart is calculated for the averaged geographical longitude and the averaged geographical latitude of both natal charts.
  Latitude (DRC) = (latitude chart 1 + latitude chart 2) / 2
  Longitude (DRC) = (longitude chart 1 + longitude chart 2) /2.
• "Davision Relationship Chart, corrected": The chart is calculated for the averaged geographical longitude and the averaged geographical latitude. However, the time is corrected in such a way that the resulting MC is the same as the composite MC of both charts. This is the classical calculation method of the Davison Relationship Chart. (see also "Composite Chart")
• "Davison Relationship Chart, reference place": The chart is calculated for a certain reference place (e.g. the common place of residence of the people concerned). The reference place can be set in the "Extended Chart Selection" under "Default settings".
• "Davison Relationship Chart, spherical midpoint": The chart is calculated for the shortest distance between both birth places, the so-called "spherical midpoint". If both birth places are a long way apart, e.g. in Hawaii and in Switzerland, the resulting spherical midpoint can lie close to the geographical north pole. This method therefore often leads to problems with the house system.

The Davison Relationship Chart is a horoscope for the midpoint of two people's birth times.

There are the following variants of the Davison Relationship Chart (DRC):

• "Davison Relationship Chart, uncorrected": The chart is calculated for the averaged geographical longitude and the averaged geographical latitude of both natal charts.
  Latitude (DRC) = (latitude chart 1 + latitude chart 2) / 2
  Longitude (DRC) = (longitude chart 1 + longitude chart 2) /2.
• "Davision Relationship Chart, corrected": The chart is calculated for the averaged geographical longitude and the averaged geographical latitude. However, the time is corrected in such a way that the resulting MC is the same as the composite MC of both charts. This is the classical calculation method of the Davison Relationship Chart. (see also "Composite Chart")
• "Davison Relationship Chart, reference place": The chart is calculated for a certain reference place (e.g. the common place of residence of the people concerned). The reference place can be set in the "Extended Chart Selection" under "Default settings".
• "Davison Relationship Chart, spherical midpoint": The chart is calculated for the shortest distance between both birth places, the so-called "spherical midpoint". If both birth places are a long way apart, e.g. in Hawaii and in Switzerland, the resulting spherical midpoint can lie close to the geographical north pole. This method therefore often leads to problems with the house system.

The Davison Relationship Chart is a horoscope for the midpoint of two people's birth times.

There are the following variants of the Davison Relationship Chart (DRC):

• "Davison Relationship Chart, uncorrected": The chart is calculated for the averaged geographical longitude and the averaged geographical latitude of both natal charts.
  Latitude (DRC) = (latitude chart 1 + latitude chart 2) / 2
  Longitude (DRC) = (longitude chart 1 + longitude chart 2) /2.
• "Davision Relationship Chart, corrected": The chart is calculated for the averaged geographical longitude and the averaged geographical latitude. However, the time is corrected in such a way that the resulting MC is the same as the composite MC of both charts. This is the classical calculation method of the Davison Relationship Chart. (see also "Composite Chart")
• "Davison Relationship Chart, reference place": The chart is calculated for a certain reference place (e.g. the common place of residence of the people concerned). The reference place can be set in the "Extended Chart Selection" under "Default settings".
• "Davison Relationship Chart, spherical midpoint": The chart is calculated for the shortest distance between both birth places, the so-called "spherical midpoint". If both birth places are a long way apart, e.g. in Hawaii and in Switzerland, the resulting spherical midpoint can lie close to the geographical north pole. This method therefore often leads to problems with the house system.

The Multi-Composite Chart can be compared to a Composite Chart, but it is not calculated for two but for three or more people. It is supposed to give information about the respective group of people. Each planet of the multi-composite chart is placed at a "middle" position which results from the natal positions of this planet in the natal charts concerned.

Like the Composite Chart, the Ascendant, MC and houses can be calculated with two different methods: the "midpoint method" and the "reference place method".

The calculation of the composite planets can follow two different methods which we call "Multi-Composite" (or "Midpoint method") and as "Multi-Composite 2" (or "Centre of gravity method"). A more detailed description of both techniques can be found in this article.

The Multi-Composite Chart can be compared to a Composite Chart, but it is not calculated for two but for three or more people. It is supposed to give information about the respective group of people. Each planet of the multi-composite chart is placed at a "middle" position which results from the natal positions of this planet in the natal charts concerned.

Like the Composite Chart, the Ascendant, MC and houses can be calculated with two different methods: the "midpoint method" and the "reference place method".

The calculation of the composite planets can follow two different methods which we call "Multi-Composite" (or "Midpoint method") and as "Multi-Composite 2" (or "Centre of gravity method"). A more detailed description of both techniques can be found in this article.

The Multi-Composite Chart can be compared to a Composite Chart, but it is not calculated for two but for three or more people. It is supposed to give information about the respective group of people. Each planet of the multi-composite chart is placed at a "middle" position which results from the natal positions of this planet in the natal charts concerned.

Like the Composite Chart, the Ascendant, MC and houses can be calculated with two different methods: the "midpoint method" and the "reference place method".

The calculation of the composite planets can follow two different methods which we call "Multi-Composite" (or "Midpoint method") and as "Multi-Composite 2" (or "Centre of gravity method"). A more detailed description of both techniques can be found in this article.

The Progression (also called Secondary Progression) is based on the idea that there is a symbolic analogy of 1 year = 1 day in the life of a person. At 30 years of age, a chart is calculated for the 30th day after birth.

This means that we determine the current age of the native in years and then calculate the chart for the same number of days after birth. This horoscope, similar to a transit chart, can be interpreted in relation to the birth chart (synastry).

Ascendant, MC and houses are moved by about 1° per year in the progressed chart. In practice, the number of years is multiplied by the mean daily motion of the Sun. The result is then added to the sidereal time of birth, and axes and houses are recalculated. The mean daily motion of the Sun (the so-called 'Naibod key') is 0.98564733°. In fact, this is a primary direction of the angles and houses.

Other astrological software may provide slightly different positions of the angles and house cusps. E.g., Solar Fire calculates them as follows: The solar arc, i.e. the ecliptic motion that the progressed Sun has made since birth, is added to the midheaven (MC), then the ascendant and the other house cusps are calculated from this new midheaven. Astrodienst offers this as an option in the section of "Display and calculation options"/"Progressions" under the designation "MC from solar arc".

Another method of calculating the progressive axes and houses is to apply the equation 1 year = 1 day to the Earth's daily rotation. Since the meridian moves forward by about 361° within a day, it would actually be logical to let the progressive MC run forward by 361° in the course of a year of life. Astrodienst offers this progression method under the designation "ARMC 361° / prog. Day". (Strictly speaking, the other two calculation methods mentioned above for the progressive axes are not real secondary progressions, but primary directions.)

The Progression (also called Secondary Progression) is based on the idea that there is a symbolic analogy of 1 year = 1 day in the life of a person. At 30 years of age, a chart is calculated for the 30th day after birth.

This means that we determine the current age of the native in years and then calculate the chart for the same number of days after birth. This horoscope, similar to a transit chart, can be interpreted in relation to the birth chart (synastry).

Ascendant, MC and houses are moved by about 1° per year in the progressed chart. In practice, the number of years is multiplied by the mean daily motion of the Sun. The result is then added to the sidereal time of birth, and axes and houses are recalculated. The mean daily motion of the Sun (the so-called 'Naibod key') is 0.98564733°. In fact, this is a primary direction of the angles and houses.

Other astrological software may provide slightly different positions of the angles and house cusps. E.g., Solar Fire calculates them as follows: The solar arc, i.e. the ecliptic motion that the progressed Sun has made since birth, is added to the midheaven (MC), then the ascendant and the other house cusps are calculated from this new midheaven. Astrodienst offers this as an option in the section of "Display and calculation options"/"Progressions" under the designation "MC from solar arc".

Another method of calculating the progressive axes and houses is to apply the equation 1 year = 1 day to the Earth's daily rotation. Since the meridian moves forward by about 361° within a day, it would actually be logical to let the progressive MC run forward by 361° in the course of a year of life. Astrodienst offers this progression method under the designation "ARMC 361° / prog. Day". (Strictly speaking, the other two calculation methods mentioned above for the progressive axes are not real secondary progressions, but primary directions.)

The Tertiary Progression I (also called tertiary direction I) is based on the idea that there is a symbolic analogy of 1 month = 1 day, a "month" referring to the so-called tropical month of 27.32158 days. So, the age of a person is calculated in tropical months and a chart is generated for the same number of days after birth.

Unlike the progressed chart, the tertiary chart does not change continuously, but remains identical for a whole month in a person's life, i.e. it changes after the chosen month in a person's life is completed. (Method according to E.H. Troinski)

The Tertiary Progression II (Lunar) (Lunar Return of the Tertiary Progression II) was introduced by the German astrologer Klaus Wessel. It is based on the symbolic analogy of 1 year = 1 month, a "month" referring to the so-called tropical month of 27.32158 days, a "year" to the tropical year of 365.242199 days. The age of a person is calculated in years and a chart is generated for the same number of "months" after birth.

Unlike other progressed charts, the Lunar Return of the Tertiary Progression II does not change continuously, but is calculated for the progressed lunar return. It therefore remains identical for a whole year in a person's life and changes only after a year of age is completed.

The Solar Arc Direction, similar to progression, is based on the idea that there is a symbolic analogy of 1 year = 1 day in the life of a person.

The age of the native is calculated in years, and then multiplied by the mean daily motion of the Sun. The result is added to all planets, axes and houses. The solar arc chart can, like a transit chart, be interpreted in relation to the natal chart (synastry).

The mean daily motion of the Sun (the so-called 'Naibod key') is 0.98564733°.

The Progression (also called Secondary Progression) is based on the idea that there is a symbolic analogy of 1 year = 1 day in the life of a person. At 30 years of age, a chart is calculated for the 30th day after birth.

This means that we determine the current age of the native in years and then calculate the chart for the same number of days after birth. This horoscope, similar to a transit chart, can be interpreted in relation to the birth chart (synastry).

Ascendant, MC and houses are moved by about 1° per year in the progressed chart. In practice, the number of years is multiplied by the mean daily motion of the Sun. The result is then added to the sidereal time of birth, and axes and houses are recalculated. The mean daily motion of the Sun (the so-called 'Naibod key') is 0.98564733°. In fact, this is a primary direction of the angles and houses.

Other astrological software may provide slightly different positions of the angles and house cusps. E.g., Solar Fire calculates them as follows: The solar arc, i.e. the ecliptic motion that the progressed Sun has made since birth, is added to the midheaven (MC), then the ascendant and the other house cusps are calculated from this new midheaven. Astrodienst offers this as an option in the section of "Display and calculation options"/"Progressions" under the designation "MC from solar arc".

Another method of calculating the progressive axes and houses is to apply the equation 1 year = 1 day to the Earth's daily rotation. Since the meridian moves forward by about 361° within a day, it would actually be logical to let the progressive MC run forward by 361° in the course of a year of life. Astrodienst offers this progression method under the designation "ARMC 361° / prog. Day". (Strictly speaking, the other two calculation methods mentioned above for the progressive axes are not real secondary progressions, but primary directions.)

The Progression (also called Secondary Progression) is based on the idea that there is a symbolic analogy of 1 year = 1 day in the life of a person. At 30 years of age, a chart is calculated for the 30th day after birth.

This means that we determine the current age of the native in years and then calculate the chart for the same number of days after birth. This horoscope, similar to a transit chart, can be interpreted in relation to the birth chart (synastry).

Ascendant, MC and houses are moved by about 1° per year in the progressed chart. In practice, the number of years is multiplied by the mean daily motion of the Sun. The result is then added to the sidereal time of birth, and axes and houses are recalculated. The mean daily motion of the Sun (the so-called 'Naibod key') is 0.98564733°. In fact, this is a primary direction of the angles and houses.

Other astrological software may provide slightly different positions of the angles and house cusps. E.g., Solar Fire calculates them as follows: The solar arc, i.e. the ecliptic motion that the progressed Sun has made since birth, is added to the midheaven (MC), then the ascendant and the other house cusps are calculated from this new midheaven. Astrodienst offers this as an option in the section of "Display and calculation options"/"Progressions" under the designation "MC from solar arc".

Another method of calculating the progressive axes and houses is to apply the equation 1 year = 1 day to the Earth's daily rotation. Since the meridian moves forward by about 361° within a day, it would actually be logical to let the progressive MC run forward by 361° in the course of a year of life. Astrodienst offers this progression method under the designation "ARMC 361° / prog. Day". (Strictly speaking, the other two calculation methods mentioned above for the progressive axes are not real secondary progressions, but primary directions.)

The Progression (also called Secondary Progression) is based on the idea that there is a symbolic analogy of 1 year = 1 day in the life of a person. At 30 years of age, a chart is calculated for the 30th day after birth.

This means that we determine the current age of the native in years and then calculate the chart for the same number of days after birth. This horoscope, similar to a transit chart, can be interpreted in relation to the birth chart (synastry).

Ascendant, MC and houses are moved by about 1° per year in the progressed chart. In practice, the number of years is multiplied by the mean daily motion of the Sun. The result is then added to the sidereal time of birth, and axes and houses are recalculated. The mean daily motion of the Sun (the so-called 'Naibod key') is 0.98564733°. In fact, this is a primary direction of the angles and houses.

Other astrological software may provide slightly different positions of the angles and house cusps. E.g., Solar Fire calculates them as follows: The solar arc, i.e. the ecliptic motion that the progressed Sun has made since birth, is added to the midheaven (MC), then the ascendant and the other house cusps are calculated from this new midheaven. Astrodienst offers this as an option in the section of "Display and calculation options"/"Progressions" under the designation "MC from solar arc".

Another method of calculating the progressive axes and houses is to apply the equation 1 year = 1 day to the Earth's daily rotation. Since the meridian moves forward by about 361° within a day, it would actually be logical to let the progressive MC run forward by 361° in the course of a year of life. Astrodienst offers this progression method under the designation "ARMC 361° / prog. Day". (Strictly speaking, the other two calculation methods mentioned above for the progressive axes are not real secondary progressions, but primary directions.)

The Solar Return Chart is calculated for the exact time when the Sun transits the position it occupied in the natal chart. This time is close to the birthday but is not necessarily identical with the birthday, but can be a day or even two days earlier or later. Consequently, the solar return chart only changes once a year around the birtday.

If the settings use a sidereal zodiac, the solar return is calculated in relation to the sidereal position of the Sun. The date of the solar return can therefore differ from the tropical solar return chart.

The Solar Return Chart is calculated for the exact time when the Sun transits the position it occupied in the natal chart. This time is close to the birthday but is not necessarily identical with the birthday, but can be a day or even two days earlier or later. Consequently, the solar return chart only changes once a year around the birtday.

If the settings use a sidereal zodiac, the solar return is calculated in relation to the sidereal position of the Sun. The date of the solar return can therefore differ from the tropical solar return chart.

The Lunar Return Chart is calculated for the exact time when the Moon transits the position it occupied the natal chart. The lunar return chart therefore changes roughly every 27-28 days.

If the settings use a sidereal zodiac, the lunar return is calculated in relation to the sidereal position of the Moon. The date of the lunar return can therefore differ from the tropical lunar return chart.

The Lunar Opposition Chart is calculated for the exact time when the Moon is in opposition to its natal position. The lunar opposition chart therefore changes roughly every 27-28 days.

If the settings use a sidereal zodiac, the lunar opposition is calculated in relation to the sidereal position of the Moon. The date of the lunar opposition can therefore differ from the tropical lunar opposition chart.

In the Harmonic Chart, the positions of all planets are multiplied by any natural number (1, 2, 3, 4,...) and then reduced to the 360° circle. These kinds of charts are called 'harmonic' because, in music, harmonic intervals can be generated by multiplying frequencies with natural numbers. Harmonic charts could also be called "overtones" of the natal chart.

Harmonics have the useful peculiarity that certain aspects of the natal chart are turned into conjunctions in the harmonic chart. E.g., the 4th harmonic turns oppositions and squares into conjunctions (obviously, conjunctions remain conjunctions). In the 6th harmonic, all trines and sextiles appear as conjunctions. The 10th harmonic shows all decile and quintile aspects as conjunctions.

You can find more information on harmonics in the section "All about Astrology".

The Draconic Chart is the same as the natal chart but it uses the so-called draconic zodiac instead of a tropical or sidereal zodiac. The draconic chart places 0° Aries on the Moon's Node.