# Constellation geometry

Source: [d3-celestial constellation line data](https://github.com/ofrohn/d3-celestial/blob/master/data/constellations.lines.json), downloaded 11 October 2026. Copyright 2015 Olaf Frohn. The full redistribution license is in `CONSTELLATION-LICENSE.txt` and is included in the website assets.

The JSON and module contain a subset of twelve source constellation outlines. Right ascension and declination are projected with a single uniform scale for each chart, retaining its line geometry. RA is unwrapped across the 180-degree seam; east is to the left. This is a schematic chart projection, not a live astronomical sky simulation.

Course markers occupy a subset of the chart's star anchors. Unassigned chart stars remain visible. STE uses Orion; GTE uses Cassiopeia; HWR uses Aquarius; TRE uses Cygnus; CTM uses Lyra. Shared terms use additional source constellations. Cyan constellation outlines are visual geography; warm dashed links represent actual curriculum prerequisites. Course IDs and academic requirements do not depend on constellation selection.