Fr.: rotation galactique
The revolving of the gaseous and stellar content of a galaxy around its central nucleus. The rotation is not uniform, but differential. One revolution of the Sun within our own Galaxy takes about 220 million years, or one cosmic year.
galactic rotation problem
parâse-ye carxeš-e kahkešâni
Fr.: problème de la rotation galactique
The discrepancy between observed galaxy → rotation curves and the theoretical prediction, assuming a centrally dominated mass associated with the observed luminous material.