HYG v4.1 star catalog — AlgoLuna magnitude-limited adaptation

Source: HYG database, David Nash / Astronomy Nexus
https://github.com/astronexus/HYG-Database
Source revision: c7f7f883fe678cc7680169a50ccd7dcc49b060ce
Source CSV: https://raw.githubusercontent.com/astronexus/HYG-Database/c7f7f883fe678cc7680169a50ccd7dcc49b060ce/hyg/CURRENT/hygdata_v41.csv
Source SHA-256: d9f69fd86bbf90a4e4d52b4c5c53eacfa6dfc0bfdef85bfd94f095e0bebe4ebd

HYG v4.1 and this adapted data file are licensed under Creative Commons
Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).
https://creativecommons.org/licenses/by-sa/4.0/
Legal code: https://creativecommons.org/licenses/by-sa/4.0/legalcode

Changes by AlgoLuna: exclude the Sun; retain stars with apparent visual
magnitude <= 7.5; retain HYG ID, RA, declination, magnitude and B-V index;
retain available proper names in a separate ID-keyed map;
convert RA from hours to degrees; round RA/declination to 5 decimal places
and B-V to 3 decimal places; sort by magnitude/ID; serialize as compact JSON.
Selected stars: 25,791. Positions are epoch/equinox J2000.0.

No endorsement by the source authors is implied. Catalog attribution and
share-alike terms apply to the adapted catalog data. The independently
written website and camera renderer are separate from that data adaptation.