Caelus
Getting Started

Quickstart

Caelus computes a chart from a UT instant and a location. The core does no I/O, so the same code runs in the browser, on edge runtimes, and in Node.

Install

Terminal
npm install caelus

Compute a chart

Pass the engine its dataset explicitly. The embedded dataset is bundled with the package and needs no files on disk.

chart.ts
import { Engine, fmtLon } from "caelus";
import { embeddedData } from "caelus/data-embedded";

const engine = new Engine(embeddedData);

// year, month, day, hour, minute, second (UT), lat, lon (east+), house system
const chart = engine.chart(1990, 6, 10, 14, 30, 0, 27.95, -82.46, "placidus");

fmtLon(chart.bodies.sun.lon);   // "19°27' Gemini"
chart.bodies.saturn.retrograde; // true
chart.angles.asc;               // ascendant longitude, degrees

What you get back

The chart object carries every body with its longitude, speed, retrograde flag, sign, and equatorial coordinates, plus the angles, house cusps, and aspect list. See Computing Charts for the full shape.

Next steps