"In 1913, Willem de Sitter suggested that fast-moving binary stars... could be used to measure the effect of a moving source on the speed of light. Various experiments of this sort over the past eight decades have verified that the speed of light received from a moving star is the same as that from a stationary star... a wealth of other detailed experiments have been carried out during the past century..."
January 1, 1970
https://en.wikiquote.org/wiki/Willem_de_Sitter