Celestial positions and catalog information: OpenNGC, Mattia Verga and contributors.
Source: https://github.com/mattiaverga/OpenNGC
License: Creative Commons Attribution-ShareAlike 4.0 International
https://creativecommons.org/licenses/by-sa/4.0/
Adaptations: field selection, coordinate conversion to decimal units, normalized identifiers, familiar display aliases, and planetary search entries.
Retrieved September 13, 2026. Coordinates are J2000.

This adapted catalog, including the featured subset in ../../lib/featured-objects.json,
is distributed under CC BY-SA 4.0, not the application code's MIT license.
Adaptations by standon99, 2026. Preserve attribution, identify modifications, and
share further adaptations of this catalog under CC BY-SA 4.0.
The complete license is included in LICENSE.txt beside this file.
Upstream acknowledgments and contributors are preserved in ../licenses/OpenNGC-README.md
and ../licenses/OpenNGC-AUTHORS.txt, including NED, HyperLEDA, SIMBAD, HEASARC,
and Harold Corwin's NGC/IC Positions and Notes.