{
  "schemaVersion": 1,
  "revision": "method-v1-2026-08-05",
  "datasets": {
    "stars": {
      "path": "/data/stars.json",
      "sha256": "a3e3037b81fa309dcb984b5b554605d4cf58b02dfa4f7715bc732e2a09bc96af",
      "recordCount": 8921,
      "sourceDescription": "HYG-derived local export; upstream version unverified",
      "upstreamVersion": null,
      "includesSunRecord": true,
      "renderedSun": false,
      "maximumMagnitude": 6.5
    },
    "constellations": {
      "path": "/data/constellations.json",
      "sha256": "2c47c2189a857fcbf39f5f0a8790e32b0f7b40b96c659a4dbbf14320581a4218",
      "recordCount": 88,
      "uniqueAbbreviations": 88,
      "representation": "conventional line segments",
      "officialIauBoundaries": false
    }
  },
  "method": [
    "Convert the selected local civil time to UTC with the IANA time zone and daylight-saving rules for the chosen place.",
    "Convert UTC to Julian Date.",
    "Calculate Greenwich Mean Sidereal Time, then Local Sidereal Time from longitude.",
    "Transform fixed right ascension and declination into observer-based horizontal coordinates.",
    "Discard records below the geometric horizon and outside the selected shape.",
    "Apply a zenith-centred stereographic projection and render conventional constellation line segments."
  ],
  "limitations": [
    "The source file contains one Sun record, but the renderer skips it; the Moon and planets are not plotted.",
    "The renderer does not apply precession or individual stellar proper motion.",
    "The renderer does not model atmospheric refraction, terrain, weather, or light pollution.",
    "When a local wall time is skipped or repeated during a daylight-saving transition, the current renderer uses a deterministic fallback instead of asking which instant was intended.",
    "The optional Milky Way is a procedural artistic layer, not an astronomical survey image.",
    "Constellation line segments are conventional visual guides; the dataset contains no official IAU boundary polygons.",
    "The result is a commemorative illustration, not a research or observation tool."
  ],
  "sources": [
    {
      "name": "HYG Database project",
      "url": "https://github.com/astronexus/HYG-Database"
    },
    {
      "name": "US Naval Observatory — sidereal time",
      "url": "https://aa.usno.navy.mil/faq/GAST"
    },
    {
      "name": "ESA — Hipparcos overview",
      "url": "https://www.esa.int/Science_Exploration/Space_Science/Hipparcos_overview"
    },
    {
      "name": "International Astronomical Union — constellations",
      "url": "https://iauarchive.eso.org/public/themes/constellations/"
    }
  ]
}