The brightest star in the night sky is Sirius, which is also known as the Dog Star. It is located in the constellation Canis Major and is part of the larger Sirius star system. Sirius is a binary star system composed of two stars, Sirius A and Sirius B. Sirius A is the brightest star in the night sky, with an apparent magnitude of -1.46. It is about twice as massive as the Sun and has a surface temperature of around 9, 940 K.