Tyche is a static Hellenistic astrology chart creator built with plain HTML, CSS, and JavaScript.
It calculates a browser-side natal chart with:
- Tropical zodiac and Whole Sign Houses by default.
- The seven visible planets as the strict base set.
- Ascendant, MC, IC, sect, essential condition, lots, and configurations.
- English/Spanish UI.
- Day/night theme.
- Local serif typography and responsive mobile-first layout.
Planetary positions are calculated locally in the browser with vendored Astronomy Engine, an MIT-licensed JavaScript ephemeris library with approximate +/-1 arcminute accuracy. Critical charts should still be checked against professional ephemerides.