Frequently asked questions
Circular Charts > Composite Charts
- What is a composite
chart?
The composite chart is calculated as an "average chart" from the natal charts of both partners. The composite Sun is exactly half-way between both natal Suns, the composite Moon is half-way between the two natal Moons, etc. So, if one of the partners has the Sun at the beginning of Aries and the other at the beginning of Gemini, the composite Sun is at the beginning of Taurus. This results in an chart that looks like an ordinary natal chart of a person, which contains information about the nature of the partnership or relationship.
More information on the interpretation of composite charts can be found in the AstroWiki
- What is the difference between
the different kinds of composite charts?
In the "Extended Chart Selection", there are two types of composite charts which only differ in the way the house system is calculated:a) "Composite Chart, midpoint-method"
With this method the positions of the Ascendant, Midheaven and all the house cusps are calculated in the same way as the positions of the planets. This means that, for example, the composite Ascendant is on the midpoint between the two Ascendants of the partners.b) "Composite Chart, reference place method"
Apart from these two types, the "Extended Chart Selection" also lists a "Composite + Natals, midpoint-method". This is a chart drawing that shows the composite (type a) as well as the two natal charts.
With this method, first the composite MC is calculated as midpoint between the two natal MCs. Then from this MC (or rather from the corresponding natal sidereal time or ARMC) the Ascendent and house cusps are calculated for the geographical latitude of the reference place.
(The obliquity of the ecliptic is also calculated by using the mean value of the birth data.)
Special case of Venus and Mercury
When calculating a composite chart, it is possible that Mercury and Venus are almost in opposition to the Sun, a position which is impossible in reality. Some astrologers add 180° in these cases, so that the planet remains close to the Sun. Other astrologers don't do this. Thus it is possible that a composite chart which is calculated with the Astrodienst standard method, Venus is opposite the Sun; however, if it is calculated with the Huber method (also at Astrodienst), Venus is conjunct the Sun.
More information on the interpretation of composite charts can be found in the AstroWiki.
- Is there a way of adding a
composite chart to My Astro? I would like to use it like a
'normal' chart for synastry, astromaps, etc.
Unfortunately, there is no way of doing this. A composite chart cannot be used as a 'normal' chart, because it isn't one. It does not refer to real planetary constellations but is a mere mathematical construction. Therefore it cannot be used with many astrological techniques such as progressions, lunar or solar returns.
The way we store charts in a user profile is the storage of a date, time and location only. No planetary positions are stored, they are computed each time they are needed for display.However, the extended chart selection offers composite charts that are based on the progressed charts of both partners further down the list:
a) "Progressed composite chart, midpoint method"
b) "Progressed composite chart, reference place"
Furthermore, we offer a "Progressed composite + progressed natals, midpoint method".The methods of calculation are exactly the same as with the ordinary composite charts, except that the progressed charts of the partners are used instead of the natal charts.
If you want to do a synastry with a composite chart, you can show a composite chart with transits outside, by showing the composite and then clicking the button 'with transits'.
Now, if before showing the composite you set 'start date' to the birthday of the person you want to see synastry with, you can approach what you desire.
Clicking on 'with transits' will then use that date, instead of today's date.
- Can a composite chart contradict
the synastry chart?
Both of the techniques represent quite different perspectives, and of course this may result in contradictions.
The composite is a third chart that is calculated from two individual charts. It shows the dynamic of a the relationship as an independent (third) entity. Synastry compares two charts and shows what two people "trigger" in each other.
Just like people are contradictory in themselves, their relationships are not free of contradictions either.
You can find more information on synastry and composite charts in the AstroShop or in this article by Liz Greene on composite charts.
- What are multi-personal
composite charts (multi-composites) and how are they calculated?
A multi-composite chart is calculated as a "mean chart" for more than two people. Astrodienst allows multi-composite charts for up to 20 birth data.
Again, there are several different techniques:
a) "Multi-Composite, reference place"
b) "Multi-Composite, midpoint method"
c) "Multi-Composite, center of gravity method, with ref. place"
d) "Multi-Composite, center of gravity method, without ref. place"
Both techniques a) and b) work in a similar way to the ordinary composite charts.
This leaves us to explain what distinguishes the techniques a) and b) from c) and d).
With a) and b), a "balance point" between the natal planets of the people involved is found, a mean value of all birth positions.
With c) and d), however, the "center of gravity" is calculated towards which all the natal planets are drawn.
(For technical experts: With a) and b) the composite point is defined as to keep the standard deviation of the natal planets at a minimum. With c) and d), the composite point results from the addition of the positional vectors of the natal planets.)You can find more detailed technical explanations on Multi-Composites in the article Multi-personal Composite Charts.
More information on the interpretation of composite charts can be found in the AstroWiki