dso/dso.json

Built by Meridian (.github/scripts/build_dso.py) from OpenNGC by Mattia Verga (https://github.com/mattiaverga/OpenNGC):
every Messier object plus the NGC and IC objects of magnitude 10.5 or brighter, with positions (J2000, from NED),
magnitudes, sizes, position angles, surface brightness, types and redshifts. M102 is taken as NGC 5866 (Spindle Galaxy).

OpenNGC is licensed under the Creative Commons Attribution-ShareAlike 4.0 International licence (CC BY-SA 4.0), and so
is this derived file: https://creativecommons.org/licenses/by-sa/4.0/legalcode

The licence applies to dso/dso.json only, not to the rest of the site.