SIRIUS - With an apparent magnitude of −1.47, it is the brightest star in the night sky, only Moon, Venus, Jupiter and Mars are brighter. Sirius can be seen from almost every region of the Earth's surface (those living north of 73 degrees cannot see it) and, in the Northern Hemisphere, is known as a vertex of the Winter Triangle. Sirius can even be observed in daylight with the naked eye under the right conditions. Ideally the sky should be very clear, with the observer at a high altitude, and the star passing overhead, and the sun low down on the horizon.
At a distance of 8.6 light years, the Sirius system contains two of the eight nearest stars to Earth. This proximity is the reason for its brightness, as with other near stars such as Alpha Centauri and in contrast to distant, supergiants such as Canopus, Rigel and Betelgeuse. The closest large neighbouring star to Sirius is Procyon.
