NightSeam — Third-party notices & credits
=========================================

NightSeam itself is released under the MIT License (see LICENSE).

The following components, data sets and services are used and come with
their own terms:

Catalog data — OpenNGC (CC BY-SA 4.0)
-------------------------------------
The deep-sky catalog (Messier + NGC/IC, ~12,000 objects) is derived from
OpenNGC:

    OpenNGC — a dataset of NGC and IC objects
    https://github.com/mattiaverga/OpenNGC
    © (see the OpenNGC repository for authors), licensed under the
    Creative Commons Attribution-ShareAlike 4.0 International License
    (CC BY-SA 4.0). To view a copy of this license, visit
    https://creativecommons.org/licenses/by-sa/4.0/

The Messier designations themselves are public-domain (Charles Messier's
original catalog, 18th century).

Changes made to the OpenNGC-derived data: field selection and light
normalization to the application's data model; no object data was invented.

Astronomy algorithms
--------------------
Sun/moon positions, twilight, refraction and precession are implemented
after published algorithms in:

    J. Meeus, "Astronomical Algorithms", 2nd ed., Willmann-Bell, 1998

(the algorithms themselves are mathematical facts and not copyrightable;
this implementation is original code.)

Object example images — Wikimedia
---------------------------------
Example photos of objects are fetched at runtime from Wikipedia /
Wikimedia Commons, and a subset is bundled with the web version. Each image
is the work of its individual author and remains under its own license
(typically CC BY-SA, CC BY, or public domain). Per-image credit and license
details are available on the file pages:

    https://commons.wikimedia.org/
    (search for the object's name, e.g. "Messier 42")

Weather — Open-Meteo
--------------------
Weather data for observing sites is fetched from the Open-Meteo API:

    https://open-meteo.com/
    Weather data © Open-Meteo.com, free for non-commercial use.
    https://open-meteo.com/en/terms

Browser & OS runtime components
-------------------------------
The Windows executable embeds a Python 3.12 runtime plus:
FastAPI, uvicorn, Starlette, Pydantic, pywebview, PyInstaller bootloader —
all under permissive (BSD/MIT/Apache-2.0) licenses. Their license texts are
distributed in the package source tree (.venv-build site-packages) and are
available on request.

Meteor shower display data — public domain/general reference sources.

If you believe a credit is missing or incorrect, please open an issue on the
project's repository.