# Celestial Data

> Celestial datasets in GeoJSON and GeoPackage format, derived from d3-celestial and processed with R and sf by dieghernan.

The objects describe the J2000 epoch and include stars, constellations, asterisms, deep-sky objects and the Milky Way. The project represents these objects as geographic geometries in EPSG:4326, bounded by [-180, -90, 180, 90]. This representation does not turn the datasets into terrestrial observations or current celestial positions. GeoJSON files also have minified variants.

The original d3-celestial data is attributed to Olaf Frohn. Consult the repository license and citation metadata when reusing the data.

## Documentation

- [Project overview](https://dieghernan.github.io/celestial_data/): Scope and distribution options.
- [README](https://raw.githubusercontent.com/dieghernan/celestial_data/main/README.md): Plain-text project description, file inventory and citation.
- [Interactive preview](https://dieghernan.github.io/celestial_data/preview): Select datasets, inspect geographic geometry previews and download GeoJSON; large catalogs may take longer to load. This is not a location-based sky viewer.
- [Downloads](https://dieghernan.github.io/celestial_data/downloads/): Dataset catalog grouped by category, with file sizes, direct downloads and individual dataset pages.
- [Data documentation](https://raw.githubusercontent.com/dieghernan/celestial_data/main/_pages/data.md): Formats, coordinate conventions and field descriptions. Individual dataset pages linked from Downloads provide Dataset JSON-LD.
- [Sources](https://raw.githubusercontent.com/dieghernan/celestial_data/main/_pages/sources.md): Original data sources and references.

## Data and citation

- [Data files](https://github.com/dieghernan/celestial_data/tree/main/data): GeoJSON, GeoPackage and supporting CSV files.
- [Milky Way GeoJSON](https://dieghernan.github.io/celestial_data/data/mw.min.geojson): A directly downloadable example.
- [Citation metadata](https://raw.githubusercontent.com/dieghernan/celestial_data/main/CITATION.cff): Machine-readable citation information.
- [License](https://raw.githubusercontent.com/dieghernan/celestial_data/main/LICENSE): Repository license.

## Optional

- [Source repository](https://github.com/dieghernan/celestial_data): Project history and processing assets.
- [Author](https://dieghernan.github.io/): dieghernan's personal site.