Main Preferences: House System

Selection and fine-tuning of the house system.

The default house system is selected here. In addition to common systems (Placidus, Koch, Porphyry, Regiomontanus, etc.), ZEUS features unique proprietary algorithms. Some systems deserve special mention:

• Meridian — an analog of the Zariel system. In this system, 12 equal parts of the celestial equator are projected onto the ecliptic via hour circles. The MC longitude, taken as the cusp of the 10th house, defines the reference point. The cusp of house I in the axial house system is the equatorial ascendant. Thus, to find the coordinates of the house cusps, one must add multiples of 30° to the right ascension of the MC and convert the resulting right ascensions of the cusps into zodiacal longitude (Axial house system).
• Ascendant — an equal house system from the Ascendant.
• Earth — an equal house system from the cusp of the 1st house corresponding to 0° Libra.
• Solar — an equal house system from the cusp of the 4th house corresponding to the ecliptic longitude of the Sun.
• Lunar — an equal house system from the cusp of the 10th house corresponding to the ecliptic longitude of the Moon.
• Nodal — an equal house system from the cusp of the 1st house corresponding to the ecliptic longitude of the true North Node.
• Nodal Mean — an equal house system from the cusp of the 1st house corresponding to the ecliptic longitude of the mean North Node.
• Theon (from As) — also known as the place system of Theon of Alexandria. The cusps of this system are not required to be symmetrical (except for houses 1 and 7). The determination of places can be from any aphetic point. In this case — from the Ascendant.
• Hipparchus (from As) — analogous to the previous system, but calculations are based on right ascensions rather than oblique ascensions.
• Hipparchus (from MC) — analogous to the previous system, but places are calculated relative to the Meridian.
• Theon (I) — the calculation of the Ptolemaic place system begins from the object acting as the Princeps (see below).
• Hipparchus (I) — the calculation of the Hipparchan place system begins from the object acting as the Princeps (see below).
• Ptolemy — an equal house system from the Ascendant, but with a 5° shift against the zodiacal direction.
• Princeps (HSA) — this option allows calculating thematic horoscopes from any object in the chart in line with Hamburger School of Astrology techniques. The essence of the system is that an equal house system is built from the selected object (the Princeps), which can be placed on the cusp of the 1st, 4th, 7th, or 10th house corresponding to the ecliptic longitude of the object. This system is often used by Uranian astrologers. The object relative to which the thematic horoscope is to be built is selected from the adjacent Princeps box.
• Custom Ascendant — allows building an equal house system in which the selected object (from the Sun to Pluto), a fixed coordinate, or a combination of both will be on the cusp of the 1st house.
• Porphyry from Vertex — where the Antivertex is the cusp of house 1, Vertex is cusp 7, MC is cusp 10, IC is cusp 4, and the remaining cusps are trisections of these quadrants.

Note: Princeps is the planet relative to which the thematic horoscope is built in the house systems: Princeps (HSA), Ptolemy (I), Hipparchus (I).

If the following is selected as the Princeps in the Princeps (HSA) system:

• MC — a Meridian horoscope will be built
• AS — equal house, AS on cusp I
• Sun — equal house, Sun on cusp IV
• Moon — equal house, Moon on cusp X
• Node — equal house, Node on cusp I
• Aries Point — equal house, Aries Point on cusp VII
• Other objects — equal house, object on cusp IV

ℹ️ Here is what S.N. Kovalenko says about the Ptolemaic (Theon of Alexandria) and Hipparchan place systems:
…the system is authentic and highly reliable when working with the kinematics of oblique ascension. And in fact, it is the original part of astrology. Since the effective (1, 4, 5, 7, 9, 10, and 11) and ineffective (2, 3, 6, 8, and 12) places from the horoscope for subsequent interpretations were found precisely by that system for the climate. And not by the sign=house system (that is only suitable for near-equatorial astrologers, such as Hindus). And certainly not by the trisection system. Although, the proximity of an element to the upper stake (MC) was always taken into account.

If the house system you need is not present in the house selection element, click on Houses to open the list of all systems and select the ones you need so that they appear in that element when it is opened.

For harmonic charts, only 2 equal house systems are used: from AS and from MC.

Sensitive Points Horoscopes

To quickly build an SP horoscope, use the Princeps (HSA) house system and select SP as the Princeps. An additional control element will open. Manipulations with this formula are analogous to manipulations with the HSA Formulas control block. The resulting coordinate will be the actual Princeps of the horoscope and will be placed on the cusp of house 4.

Geodetic Equivalents

The GE element reformats the house system to geodetic equivalents. You can choose GE according to Grimm-Friedrich or according to Sepharial. The selection is made either from the context menu (right-click on the GE element) or in the Geodetic Equivalents block below. Here you can also specify which house system will appear in the calculation tables:

• Same as for chart — as in the selected house system for the chart.
• 5° Rule — objects located 5 degrees before a house cusp will be considered to already be in that house.
• Mundane Position — the mundane position of objects will be taken into account.
• House = Sign — whole sign house system.

Thematic Houses

The TH element modifies the current house system algorithm so that the selected object is treated as the Asc.