The people and open resources behind the app and its shared sky maps.
HYG Stellar Database v4.1 by David Nash / Astronexus, licensed under CC BY-SA 4.0.
Simply Sky selects 50 standalone stars and 647 pattern-support stars, maps the catalog fields into JSON, and projects their positions onto the sky map. Catalog B−V color indices provide restrained representative star tints. Gamma Cassiopeiae uses its Bayer name in place of Cih. The adapted catalog remains under the same license.
85 connecting figures are adapted from the Stellarium modern sky culture by Stellarium’s team, under CC BY-SA 4.0. The source links identify the exact catalog and figure revisions used.
The adaptation maps HIP star identifiers to HYG records, deduplicates edges, and preserves the two disconnected parts of Serpens. The original Orion, Cassiopeia, Crux and Big Dipper figures were authored for Simply Sky and are also licensed under CC BY-SA 4.0.
These are illustrative connecting figures, not official constellation boundaries. No Stellarium illustrations, boundary maps or descriptive prose are included.
The adapted star data, connecting figures and star-map adaptations are licensed under CC BY-SA 4.0. This license does not cover the entire application or website.
Licensed material is provided as-is, without warranties. See the license’s warranty disclaimer and terms for details.
Astronomy Engine by Don Cross, © 2019–2025, under the MIT License. The bundled astronomy calculation source is unchanged from that revision.