Mountains under a starry sky — about page imagery

About · পরিচিতি

How TaraKotha calculates

TaraKotha keeps astronomy, Vedic rules and interpretation in five separate layers. The point of that separation is simple: no number on this site is ever written by hand or guessed.

1 · Astronomical engine

Planetary positions come from the astronomy-engine library (VSOP87 for the planets, a truncated ELP-2000 series for the Moon). It returns geocentric ecliptic longitudes of date. Rahu and Ketu are the lunar nodes, computed from Meeus' mean-node series with the periodic corrections applied for the true node option. Nothing in this layer knows anything about astrology.

2 · Vedic rules

Tropical longitudes are converted to sidereal by subtracting the Lahiri (Chitrapaksha) ayanamsa, anchored at 23.85319° for J2000.0 and propagated with the IAU 2006 general precession-in-longitude polynomial. Signs, nakshatras, padas, the ascendant, houses, Vimshottari Dasha, yogas, doshas, Panchang limbs and the eight kootas are all derived from those numbers by explicit, deterministic rules. Every rule that fires is printed next to its result.

3 · API

The calculation layer is exposed over plain JSON endpoints. Charts are always recomputed on the server — a chart posted from a browser is never trusted or stored as-is.

4 · Interface

The pages you see only render values that the layers above produced. Where a value genuinely cannot be computed — a moonrise that does not occur at a polar latitude, for example — the interface says so instead of printing a plausible-looking number.

5 · Interpretation

The written explanation reads the finished chart and puts it into words. It is never permitted to calculate a degree, sign, nakshatra, house, dasha period or transit. If the interpretation layer is unavailable, the numbers are still complete on their own.

Default settings

Zodiac
Sidereal (Nirayana)
Ayanamsa
Lahiri / Chitrapaksha
House system
Whole sign (Parashari) — the rashi holding the lagna is bhava 1
Lunar node
Mean node (true node available)
Chart style
North Indian (South Indian also available)
Vimshottari year
365.25 days

Timezone and birthplace

You enter the local clock time at the birth place. Searching for the place returns its latitude, longitude and IANA timezone, and you can verify or override all three. The local time is then converted to universal time using the historical rules of that timezone — so wartime offsets and long-abolished daylight saving periods are honoured rather than approximated with a fixed offset.

Known simplifications

  • • The ayanamsa is a polynomial fit anchored at J2000.0, accurate to a few arcseconds over the historical range — far below the 3°20′ resolution of a pada.
  • • The Yoni koota uses a documented three-tier scoring matrix rather than the full classical 14×14 table.
  • • The Vashya koota uses a documented group rule with half-sign precision for Dhanu and Makara.
  • • The East Indian (Bengali) chart style is not drawn yet; North and South Indian styles are.

Astrology disclaimer

Astrological information and interpretations on this website are based on traditional astrological systems and are provided for informational and entertainment purposes. They should not be considered scientific, medical, legal or financial advice.

Read the full disclaimer