The star 70 Ophiuchi (fig. 3) may be regarded as typical of a binary system.
In this figure ak′b is an isothermal, ak″ is the curve for the binary system, and K is the ternary critical point.
In this way we get the freezing point curve Ak1B for the binary system; k1; being an eutectic point.
This star is a binary system and the light of the two components together is about the same as that of Capella (Alpha Aurig).
Two centuries ago the distinguished philosopher and mathematician, Leibnitz, proposed a binary system of numeration.
The close pair is a binary system with a long period of revolution, estimated at about two hundred years.
It is not known that they constitute a binary system, because no certain evidence of motion has been obtained.