universe-data

Star catalog tiles for Universe Atlas (chrisjz/universe) — served straight from this repo via GitHub Pages at https://data.universeatlas.org/.

Contents

stars/
  manifest.json      chunk index (files, star counts, source attribution)
  chunk-*.bin        LOD 0 — ATHYG brights (mag ≤ 11), brightest first
  gaia-b<B>-p<P>.bin LOD 1+ — Gaia DR3 band B (11–11.5, 11.5–12, 12–12.5,
                     12.5–13), HEALPix level-0 sky tile P (0–11)

Each tile is a run of 16-byte little-endian star records:

f32 x, y, z   position, scene meters (sun frame, pre-orientation convention)
u8  r, g, b   color from B−V / BP−RP via blackbody temperature
u8  s         absolute magnitude, s = (absmag + 15) · 8

The atlas streams tiles brightest-first from manifest.json; the tile scheme is hierarchical LOD (magnitude bands) × spatial (HEALPix level-0), so a session only downloads what it renders. Regenerate with scripts/generate-gaia-tiles.mjs in the main repo (chunked, resumable download from ESA’s TAP archive).

Data credits & licenses

• Gaia DR3 — This work has made use of data from the European Space Agency (ESA) mission Gaia, processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Credit: ESA/Gaia/DPAC, free use with attribution. Cut: 11 ≤ G < 13, parallax_over_error > 5; distances are 1/parallax.
• ATHYG v3.2 — astronexus/ATHYG-Database (Tycho-2 + Gaia DR3 merge), CC BY-SA 4.0.

The tile data in stars/ is derived from both catalogs and is provided under CC BY-SA 4.0.