# Data attributions

- **stars.bin, star-designations.json** — derived from the [HYG Database](https://github.com/astronexus/HYG-Database)
  (David Nash, astronexus.com), licensed **CC BY-SA 4.0**; these derived files remain
  shareable under the same license. Regenerate with `node scripts/build-star-data.mjs`
  (source CSV in `data-src/`, download instructions in the script header).
- **comets.json** — orbital elements and photometric parameters (M1/K1) from the
  [JPL Small-Body Database](https://ssd.jpl.nasa.gov/tools/sbdb_query.html) (NASA/JPL,
  **public domain**). Regenerate with `node scripts/build-comet-data.mjs`.
- **meteor-showers.json** — curated for this project from published IMO/IAU Meteor Data
  Center shower parameters (radiants, activity windows, ZHR, speeds — factual catalog data);
  descriptive text original.
- **constellations.lines.json, constellations.json, constellations.borders.json** —
  from [d3-celestial](https://github.com/ofrohn/d3-celestial) (Olaf Frohn), **BSD-3-Clause**;
  underlying data compiled from public astronomical catalogs (Hipparcos, IAU boundaries per Delporte 1930).
- **fixed-stars.json, constellations-meta.json** — original content written for this project
  (traditional astrological attributions after Ptolemy, Agrippa, and Robson; public-domain sources).
- **/textures/2k_\*.jpg** — planet/Moon/Sun surface maps from
  [Solar System Scope](https://www.solarsystemscope.com/textures/), **CC BY 4.0**
  (based on NASA elevation and imagery data). Saturn's ring texture is generated
  procedurally at runtime (see Planets.tsx).

User-facing credits live on [/sky/about](/sky/about) (Data sources section), which links
here. CC BY-SA requires that attribution survive into any public deployment.

## Place gazetteer (public/data/cities.json + the `places` table)

Birth-place lookup on /chart, /compatibility and /returns is built from the
GeoNames geographical database (https://www.geonames.org/), licensed
CC BY 4.0. We use the `cities500` dump (every populated place over roughly
500 people) together with `admin1CodesASCII` to resolve region names, taking
name, country, region, coordinates and IANA timezone for each place.

The bundled JSON holds the ~8,000 places over 50,000 people, so the picker
answers instantly and still works with no network. The full ~210,000 are
searched server-side. Rebuild both with `node scripts/build-city-data.mjs`.

CC BY 4.0 requires that attribution survive into any public deployment; the
credit on /sky/about links here.

## Glyph fonts (public/fonts/)

Astrological symbols are rendered from two Google Noto subsets, licensed
under the SIL Open Font License 1.1:

- `aspicio-glyphs-1.woff2` — Noto Sans Symbols, cut to the Moon through
  Pluto, the twelve signs, both nodes, Chiron, conjunction, opposition,
  and sextile.
- `aspicio-glyphs-2.woff2` — Noto Sans Symbols 2, cut to the Sun, the
  square and trine marks, and the moon-phase discs.

Both were subset with fontTools to only the codepoints the site draws
(~6KB combined) and are declared as one family in `globals.css`.