Catalogs used by the astronomical-object lookup are listed here with their licenses and release details.
Solar System positions, illumination, and constellations are calculated locally in the visitor browser with Astronomy Engine by Don Cross.
Site- and night-specific comet discovery is provided by the Comet Observation Database (COBS).
Geocentric comet right ascension, declination, and magnitude ephemerides are provided by NASA/JPL Horizons.
Sky visualization data derived from d3-celestial by Olaf Frohn. Star positions and magnitudes are based on XHIP; constellation lines and labels use IAU constellations; the Milky Way layer uses the Milky Way Outline Catalog.
OpenNGC by Mattia Verga and contributors.
Deep-sky object names from Stellarium and the sources credited in its names.dat catalog.