These files contain geometries outlining the Milky Way isophotes at five levels of surface brightness.

The files are based on the one provided on the d3-celestial plugin by Olaf Frohn with cleanup by Diego Hernangómez.

For mw.json, using geojson.io I reworked manually the polygons at the -180º=180º RA boundary to avoid large gaps.

For mw_simplified.json I also used mapshaper.org 'simplify' command (with percentage=43%). This allowed for a >50% reduction in file size with very little degradation of the polygons.

Both files were exported with mapshaper.org back to GeoJSON using the parameter precision=0.001 as the original.

id: Milky Way outlines in 5 brightness steps (ol1-ol5).

Frohn O, Hernangómez D (2023). “Celestial Data.” doi:10.5281/zenodo.7561601 https://doi.org/10.5281/zenodo.7561601, https://dieghernan.github.io/celestial_data/.