NIGHT SKY CLASSROOM — DATA AND CHART REUSE

Star catalogue: HYG Database v4.1, David Nash / Astronexus.
https://github.com/astronexus/HYG-Database
Pinned commit: c7f7f883fe678cc7680169a50ccd7dcc49b060ce
License: Creative Commons Attribution-ShareAlike 4.0 International
https://creativecommons.org/licenses/by-sa/4.0/
The upstream license notice is provided alongside this file as HYG-LICENSE.txt.

Bryce Canyon Conservancy adapted the catalogue by retaining stars with apparent
visual magnitude <= 5.5, excluding the Sun, selecting identifying/coordinate
fields, converting right ascension from hours to degrees, and rounding positions
to six decimal degrees. Catalogue epoch and equinox remain J2000.0; the runtime
applies precession. The runtime subset and catalogue-derived charts are offered
under the same CC BY-SA 4.0 license. Credit both the original and this adaptation,
identify any further changes, and preserve the ShareAlike terms. No endorsement
by the original author is implied.

NPS Sunset Point coordinates: National Park Service public POI object 7763,
source method NAIP, Harpers Ferry; coordinate accuracy Unknown. U.S. Government
public data. No NPS imagery is copied. Numerical NASA/JPL Horizons results are
retained in source verification records with exact requests and retrieval dates.

The astronomical code and teaching diagrams are original implementations of
documented mathematical methods. No third-party chart artwork, photograph,
software package or runtime API is bundled. Source facts and their boundaries
are recorded in sources.json. No claim is made to original government works.

Existing BCC logo and local Gelasio/Inter fonts are reused unchanged; their
existing website attribution and SIL Open Font License notices still apply.