triple star
noun
°Three stars which form a stellar system, such that they orbit the point of equilibrium of their gravitational fields; a trinary star.
°Three stars that appear to be one when seen with the naked eye, either because they orbit one another (trinary stars) or happen to be in the same line of sight even though they are separated by a great distance.
synonyms: trinary, trinary star, triple star system, trinary star system