Canis Major
Canis Major contains Sirius, the brightest star in the night sky, known as the "dog star". It is bright because of its proximity to the Solar System. In contrast, the other bright stars of the constellation are stars of great distance and high luminosity. At magnitude 1.5, Epsilon Canis Majoris (Adhara) is the second-brightest star of the constellation and the brightest source of extreme ultraviolet radiation in the night sky. Next in brightness are the yellow-white supergiant Delta (Wezen) at 1.8, the blue-white giant Beta (Mirzam) at 2.0, blue-white supergiants Eta (Aludra) at 2.4 and Omicron at 3.0, and white spectroscopic binary Zeta (Furud), also at 3.0. The red hypergiant VY Canis Majoris is one of the largest stars known, while the neutron star RX J0720.4-3125 has a radius of a mere 5 km.
List of brightest stars
This is a list of the brightest stars down to magnitude +2.50, as determined by their "maximum", "total", or "combined" visual magnitudes as viewed from Earth. Although several of the brightest stars are known binary or multiple star systems and are relatively close to Earth, they appear to the naked eye as single stars. The list below combines/adds the magnitudes of bright individual components. Most of the proper names in this list are those approved by the Working Group on Star Names. Popular star names here that have not been approved by the IAU appear with a short note.