Assertion: coordinate's position | /r/HasProperty | established at various dates
Facets:
Source sentences:
text: Mean equinox of a standard epoch (usually J2000.0, but may include B1950.0, B1900.0, etc.) is a fixed standard direction, allowing positions established at various dates to be compared directly.
text: Mean equinox of a standard epoch (usually the J2000.0 epoch, but may include B1950.0, B1900.0, etc.) is a fixed standard direction, allowing positions established at various dates to be compared directly.