THIRD-PARTY CREDITS AND LICENSE NOTICES
=======================================

This website uses third-party data, imagery, and open-source software.


HYG DATABASE v4.1
-----------------
Source: HYG Database v4.1 / astronexus
https://github.com/astronexus/hyg-database

The source catalog was filtered to stars with apparent magnitude 6.5 or
brighter and converted to JSON for this website. The adapted star catalog is
provided under the Creative Commons Attribution-ShareAlike 4.0 International
License (CC BY-SA 4.0):
https://creativecommons.org/licenses/by-sa/4.0/


NASA EARTH IMAGERY
------------------
Earth surface:
NASA Visible Earth, The Blue Marble: Land Surface, Ocean Color and Sea Ice.
NASA Goddard Space Flight Center image by Reto Stöckli; enhancements by
Robert Simmon.
https://visibleearth.nasa.gov/images/57730/the-blue-marble-land-surface-ocean-color-and-sea-ice

Earth night lights:
NASA Earth Observatory image by Robert Simmon, using Suomi NPP VIIRS data
provided courtesy of Chris Elvidge (NOAA National Geophysical Data Center).
Suomi NPP is the result of a partnership between NASA, NOAA, and the
Department of Defense.
https://svs.gsfc.nasa.gov/30028


WORLD MAGNETIC MODEL 2025
-------------------------
NOAA NCEI Geomagnetic Modeling Team and British Geological Survey, World
Magnetic Model 2025.
https://www.ncei.noaa.gov/products/world-magnetic-model
https://doi.org/10.25921/aqfd-sd83


OPEN-SOURCE SOFTWARE
--------------------
Astronomy Engine 2.1.19 — MIT License
Copyright (c) 2019-2023 Don Cross
Full license: ./licenses/astronomy-engine-MIT.txt
Source: https://github.com/cosinekitty/astronomy

three.js 0.179.1 — MIT License
Copyright (c) 2010-2025 three.js authors
Full license: ./licenses/three-MIT.txt
Source: https://github.com/mrdoob/three.js

d3-celestial 0.7.35 — BSD 3-Clause License
Copyright (c) 2015 Olaf Frohn
Full license: ./licenses/d3-celestial-BSD-3-Clause.txt
Source: https://github.com/ofrohn/d3-celestial

d3 3.5.17 — BSD 3-Clause License
Copyright (c) 2010-2016 Michael Bostock
Full license: ./licenses/d3-BSD-3-Clause.txt
Source: https://github.com/d3/d3

geomagnetism 0.2.0 — Apache License 2.0
Copyright Brandon Reavis and contributors
Full license: ./licenses/geomagnetism-Apache-2.0.txt
Source: https://github.com/naturalatlas/geomagnetism


CONSTELLATION REFERENCES
------------------------
Official 88 constellations:
International Astronomical Union
https://www.iau.org/Iau/Science/What-we-do/The-Constellations.aspx

Japanese constellation names:
National Astronomical Observatory of Japan
https://www.nao.ac.jp/new-info/constellation.html