Planetarium data provenance and reuse ==================================== bright-stars.json ----------------- Adapted from HYG Star Database v4.1 by David Nash / Astronomy Nexus and contributors. Source (pinned): https://github.com/astronexus/HYG-Database/blob/c7f7f883fe678cc7680169a50ccd7dcc49b060ce/hyg/CURRENT/hygdata_v41.csv License evidence: https://github.com/astronexus/HYG-Database/blob/c7f7f883fe678cc7680169a50ccd7dcc49b060ce/hyg/CURRENT/LICENSE Field documentation: https://github.com/astronexus/HYG-Database/blob/c7f7f883fe678cc7680169a50ccd7dcc49b060ce/hyg/README.md Original catalog and this adapted dataset: Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0). License deed: https://creativecommons.org/licenses/by-sa/4.0/ Full legal code: https://creativecommons.org/licenses/by-sa/4.0/legalcode Changes: Converted CSV to compact JSON rows, retained apparent visual magnitude <=6.5, removed Sun (HYG id 0), selected fields, sorted by magnitude and HYG id. Names fall back from proper name to Bayer/Flamsteed designation, then HIP, HR, or HYG id. No star positions are invented or rounded beyond source precision. 8,920 stars; magnitude -1.44 to 6.5; all 88 constellation abbreviations represented. RA in hours, Dec in degrees. Epoch AND equinox J2000.0. Color index B-V. No proper-motion, precession, nutation, aberration, parallax or refraction correction was applied. These are catalog positions, not apparent-of-date coordinates. Some v4.1 secondary-star names ending in B are explicitly unofficial source labels. Schema: {meta, stars}. Each star row is: [id, raHours, decDegrees, magnitude, name, constellation, hip, colorIndexBV] Missing optional values are null. All rows contain finite valid coordinates. constellation-lines.json ------------------------ Adapted from Stellarium modern sky culture by Stellarium's team, combined with HYG v4.1 star positions. This adapted dataset is also CC BY-SA 4.0. Source (pinned): https://github.com/Stellarium/stellarium/blob/f57342271c6047774f3b25991ba494600301c709/skycultures/modern/index.json License evidence: https://github.com/Stellarium/stellarium/blob/f57342271c6047774f3b25991ba494600301c709/skycultures/modern/description.md Source explicitly states: Text and data: CC BY-SA 4.0. Illustrations use a different license and are NOT included. Changes: Retained all 88 constellation line figures and names. Each source HIP polyline endpoint is joined to its exact HYG RA/Dec. All 710 unique HIP endpoints resolve. There are 219 polylines comprising 695 segments. Label positions are computed spherical means of the unique endpoints, merely for label placement. The source figure connectivity is unchanged. Two endpoints exceed magnitude 6.5: HIP 30665 (6.60), HIP 33165 (6.65); their real coordinates are retained in the line asset even though those stars are excluded from the magnitude-limited point cloud. Schema: {meta, constellations}. Each constellation has id, name (Latin), meaning (English), label [raHours, decDegrees], lines (arrays of polylines of coordinate pairs), and hipLines (corresponding source HIP identifiers). Use the coordinate pairs directly; do not assume all HIP endpoints exist in the bright-star subset. All coordinates have J2000.0 epoch and equinox. Constellation line figures are conventional visual aids, not IAU boundaries. No boundary data was transformed or supplied for direct display. The downloaded Stellarium source contains B1875 boundaries; they must not be plotted as J2000 without an appropriate frame transformation. Display and redistribution -------------------------- Suggested visible credit: Star data: HYG v4.1, David Nash / Astronomy Nexus and contributors (CC BY-SA 4.0). Constellation figures: Stellarium's team (CC BY-SA 4.0). Filtered and reformatted for this planetarium; source coordinates retained. Link both source datasets and https://creativecommons.org/licenses/by-sa/4.0/. Retain credit, source/license links and the modification notice when redistributing these adapted datasets, and offer them under CC BY-SA 4.0. This file documents data licensing; it does not purport to set a license for unrelated application code. Reproducibility and checks -------------------------- prepare-planetarium-data.py recreates the two JSON assets from local source files hygdata_v41.csv and stellarium-modern-index.json. planetarium-data-checks.json gives counts, ranges, sizes and SHA-256 checksums. Each asset embeds provenance metadata. No Site files were edited.