Assertion: asterism's star | /r/HasProperty | recognized for some time
Facets:
value: as having similar brightness
type: OTHER
Source sentences:
text: The three stars have been recognized for some time as having similar brightness (although it should be noted that Deneb is about 1,400 light-years away while Vega and Altair are roughly 20 light-years away each, showing how much more luminous Deneb is.)