Bhava Cusps

What is a bhava cusp?

A bhava cusp is a boundary longitude — the degree of the zodiac where a house begins. Twelve cusps carve the circle into the twelve houses. In the Lagna Chart’s whole-sign scheme you never think about cusps, because each house is a whole sign and its boundaries sit at 0° of each sign. The moment you move to unequal houses, the cusps become real numbers you have to compute — and they stop lining up with sign boundaries.

AstroShruti’s cusps are the arithmetic behind the Bhava Chalit chart. The Chalit tells you which bhava a planet lands in; the cusps are the edges it lands between.

How the engine computes them

The cusps come from Swiss Ephemeris’ native Sripati (‘S’) house system, built for your birth moment, latitude and longitude, and your chosen ayanamsha.

Two facts define how they are used:

1. Each cusp is a bhava start. Swiss Ephemeris returns the twelve values as the starting longitudes of the twelve bhavas, in order around the circle.
2. The lagna is the madhya of the first bhava. The ascendant is not the first cusp — it is the middle of the first house. The first cusp sits earlier in the zodiac, so the ascendant longitude falls inside the first bhava’s arc rather than at its opening edge.

For each cusp the engine records four things: the bhava number (1–12), the cusp longitude, the sign that longitude falls in, and that sign’s lord. That is the whole cusp table.

What the app shows

In the app, the Bhava Cusps atom is a compact three-column table — one row per house, in order:

The Cusp column shows the sign and the degree within it (for example a value like “Virgo 12.40°”), and the Lord column names the sign lord in the planet’s colour. Because the houses are unequal, you will typically see the degree-within- sign creep unevenly from one cusp to the next, and you will sometimes see two consecutive cusps land in the same sign or skip a sign entirely — the visible signature of unequal houses.

Read this table side by side with the Chalit: when a planet is flagged as shifted there, this table shows you why — the nearby cusp that its longitude crossed.

Sripati bhava starts versus KP cusps

This is the honest comparison worth getting right, because both systems talk about “cusps” and “unequal houses” and mean genuinely different machinery.

The load-bearing difference is the sub-lord. KP subdivides each nakshatra by the Vimshottari proportions and reads the sub-lord of a cusp’s exact degree as the deciding factor for that house’s affairs. AstroShruti’s Sripati cusps deliberately do not carry a sub-lord — they are a Parashari worksheet whose job is to place planets in unequal bhavas, not to run KP judgement. Where you need cuspal sub-lords and significators, the Cuspal Interlinks page in the KP module is the right tool, and it uses Placidus, not Sripati.

Treating a Sripati cusp as if it were a KP cusp — or reading a KP sub-lord off a Sripati boundary — mixes two systems that were never meant to share cusps. The app keeps them in separate modules for exactly this reason.

A structural note: why cusps drift off sign edges

To see why cusps matter, picture the difference from whole-sign houses. In whole-sign, cusp 2 is always 0° of the sign after the lagna’s sign — a fixed, tidy boundary. In Sripati, cusp 2 is wherever the diurnal geometry puts the start of the second bhava, which at a typical latitude might land several degrees before or after that sign edge.

So a planet at, say, 28° of the lagna’s sign — comfortably a “1st house” planet by sign — can sit past an early second cusp and belong to the 2nd bhava. The cusp table is where you confirm this: find the 2nd cusp, compare it to the planet’s longitude, and the shift is no longer mysterious. That is the entire value of publishing the cusps alongside the Chalit rather than hiding them.

Honest notes

• The cusps move with your ayanamsha. They are computed against the ayanamsha in your settings, so the exact degrees shift if you change it. The relationships (which houses are wide, which are narrow) are stable; the absolute longitudes are not.
• Sign lord, not house lord analysis. The lord column names the ruler of the sign the cusp falls in. It is a starting read, not a substitute for full house-lordship judgement from the rasi chart.
• Extreme latitudes stress the system. As with all quadrant house systems, Sripati cusps become increasingly uneven toward high latitudes. At the polar extremes house division itself becomes unstable — a limitation of the geometry, not of this implementation.

Where it connects

The Bhava Cusps feed directly into the Bhava Chalit chart, which reads planets against these boundaries, and they stand in contrast to the whole-sign houses of the Lagna Chart. For the KP treatment of cusps — Placidus boundaries with sub-lords and significators — see Cuspal Interlinks.