{
  "buildDate": "2026-10-25",
  "coordinateEpoch": "J2000.0",
  "units": {
    "ra": "hours",
    "dec": "degrees",
    "dist": "parsecs",
    "mag": "apparent visual magnitude",
    "ci": "B−V color index",
    "lum": "solar luminosities"
  },
  "starCount": 8920,
  "curatedCount": 30,
  "constellationCount": 14,
  "notes": [
    "Positions and catalog distances are HYG v4.1 values, not real-time high-precision astrometry.",
    "HYG distance >=100000 pc, missing, zero or invalid values are null; never render them as measured distances.",
    "Stellar distances are uncertain catalog estimates. No per-star distance error is included in this prototype.",
    "Stellar surfaces are illustrative except for the explicitly labelled front-hemisphere projections of Betelgeuse and Antares observations. Unobserved rear hemispheres are grey. Sirius is an unresolved point-source image, never a surface texture. See data/observations/star-assets.json.",
    "Constellation connecting lines are Stellarium Western diagrams, not IAU official boundaries.",
    "Bright-star subset: apparent magnitude <=6.5, with any required constellation vertices retained.",
    "1 parsec = 3.261563777 light years."
  ],
  "data": [
    {
      "id": "hyg",
      "title": "HYG Database v4.1",
      "author": "David Nash / Astronexus; Hipparcos, Yale Bright Star and Gliese catalogs",
      "url": "https://github.com/astronexus/HYG-Database/blob/main/hyg/README.md",
      "download": "https://raw.githubusercontent.com/astronexus/HYG-Database/main/hyg/CURRENT/hygdata_v41.csv",
      "license": "CC BY-SA 4.0",
      "licenseUrl": "https://creativecommons.org/licenses/by-sa/4.0/",
      "sha256": "d9f69fd86bbf90a4e4d52b4c5c53eacfa6dfc0bfdef85bfd94f095e0bebe4ebd",
      "adaptation": "Filtered magnitude subset; selected columns; numeric conversion; invalid distances null; Korean labels added. stars.json and curated.json remain CC BY-SA 4.0."
    },
    {
      "id": "stellarium",
      "title": "Stellarium Western sky culture",
      "author": "Stellarium team",
      "url": "https://github.com/Stellarium/stellarium-skycultures/tree/master/western",
      "download": "https://raw.githubusercontent.com/Stellarium/stellarium-skycultures/master/western/index.json",
      "license": "CC BY-SA (source description does not specify version)",
      "licenseUrl": "https://github.com/Stellarium/stellarium-skycultures/blob/master/western/description.md#license",
      "sha256": "a861accd345249a185a5ecfc2a516f34291c0aa52f4bb8d8337ffc53e9cef6b9",
      "adaptation": "14 constellation line diagrams; polylines expanded into segment pairs; Korean labels added. Retain source CC BY-SA attribution/share-alike for constellations.json."
    }
  ],
  "assets": [
    {
      "file": "assets/moon-color.jpg",
      "title": "CGI Moon Kit — LROC 2025 color map, 2048 × 1024",
      "credit": "NASA’s Scientific Visualization Studio; Ernie Wright (USRA); LRO / LROC camera team (Arizona State University)",
      "url": "https://svs.gsfc.nasa.gov/4720/",
      "download": "https://svs.gsfc.nasa.gov/vis/a000000/a004700/a004720/lroc_color_2k.jpg",
      "license": "NASA media usage guidelines; public-use visualization, credit retained",
      "licenseUrl": "https://www.nasa.gov/nasa-brand-center/images-and-media/",
      "notes": "Observation-derived color mosaic, white-balanced and optimized for visual rendering; not intended for scientific measurement."
    },
    {
      "file": "assets/moon-height.jpg",
      "title": "CGI Moon Kit — LOLA elevation map, 1024 × 512",
      "credit": "NASA’s Scientific Visualization Studio; LRO / LOLA instrument team",
      "url": "https://svs.gsfc.nasa.gov/4720/",
      "download": "https://svs.gsfc.nasa.gov/vis/a000000/a004700/a004720/ldem_3_8bit.jpg",
      "license": "NASA media usage guidelines; public-use visualization, credit retained",
      "licenseUrl": "https://www.nasa.gov/nasa-brand-center/images-and-media/",
      "notes": "8-bit preview elevation map for subtle visual bump shading; not calibrated scientific terrain."
    },
    {
      "file": "assets/earth-color.png",
      "title": "Blue Marble — Seamless Earth mosaic, 2048 × 1024",
      "credit": "NASA/Goddard Space Flight Center Scientific Visualization Studio; Blue Marble Next Generation data courtesy of Reto Stockli (NASA/GSFC) and NASA’s Earth Observatory",
      "url": "https://svs.gsfc.nasa.gov/2915/",
      "download": "https://svs.gsfc.nasa.gov/vis/a000000/a002900/a002915/bluemarble-2048.png",
      "license": "NASA media usage guidelines; public-use visualization, credit retained",
      "licenseUrl": "https://www.nasa.gov/nasa-brand-center/images-and-media/",
      "notes": "Observation-derived global composite. Not current weather or cloud cover."
    }
  ],
  "planet_parameters": {
    "source": "https://ssd.jpl.nasa.gov/planets/phys_par.html",
    "notes": "Mean radii in km; sidereal orbital periods in Julian years converted using 365.25 days. Moon/Sun radii are rounded reference values. All body orientations and surface animation speeds are illustrative."
  }
}