Zeta Puppis, also called by its traditional name Naos from the Greek ναύς "ship", or less commonly, Suhail Hadar, is one of the hottest stars in the galaxy, one of the few rare class O stars visible in the night sky, and is the second brightest such star in terms of its apparent magnitude (only Zeta Orionis appears brighter). It is located in the constellation of Puppis. Zeta Puppis is located 1,093 light years away according to the 2008 data from the Hipparcos mission.
Zeta Puppis is a blue supergiant star of spectral class O5IAf, making it one of the hottest stars in the galaxy with a surface temperature of 42,400K (in comparison, the Sun has a surface temperature of 5,780 K). The star’s mass is 59 times that of our Sun, and 20 times its diameter.
Because Zeta Puppis is an exceptionally large class O supergiant, it is one of the brightest stars in the galaxy in terms of absolute magnitude, at -5.96. The star is 21,000 times as luminous as our Sun visually. However, because it is a class O blue star, most of the radiation from the star is in the ultraviolet. When this is considered, the star is 790,000 times more luminous then the Sun overall.
Because of its temperature and luminosity, if Zeta Puppis was at the same distance as Sirius from our Solar System, it would appear as bright as a quarter-moon. If Zeta Puppis was our Sun, the Earth would have to be 450 AU away in order to maintain the same temperature and climate, or about 11 times the mean distance of Pluto from our Sun.
Zeta Puppis is a fine example of a class O "runaway" star and is moving at a speed of over 100 kilometers a second.
- Maíz Apellániz, J.; Alfaro, E. J.; Sota, A. (2008). Accurate distances to nearby massive stars with the new reduction of the Hipparcos raw data. arΧiv:0804.2553
- Lamers & Cassinelli 1999, accurate to 200 K