Assertion: coordinate system | /r/HasProperty | specified by equinox and equator
Facets:
Source sentences:
text: Astronomical data are often specified not only in their relation to an epoch or date of reference but also in their relations to other conditions of reference, such as coordinate systems specified by "equinox", or "equinox and equator", or "equinox and ecliptic" – when these are needed for fully specifying astronomical data of the considered type.