Multiple choice general knowledge science & technology Which of the following is not a Binary star system? Sirius Albireo Aldebaran Antares Reveal answer Fill a bubble to check yourself C Correct answer Explanation Aldebaran is a single red giant star in the constellation Taurus, not a binary system. Sirius is a binary system (Sirius A and B), Albireo is a famous visual double star, and Antares is a multiple star system with a companion.