Zeta Puppis

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 and 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 [[Milky Way|galaxy]} in terms of absolute magnitude, at -5.96. The star is 21,000 times as luminous as out 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.

Like all class O stars, Zeta Puppis is extremely young, estimated to be only one or two million years old, but because it is so bright and hot, the star has already burned through its hydrogen fuel. Thus the star is already dying and fusing helium into carbon and oxygen in the core. Zeta Puppis over time will cool to a red supergiant before ending its life in a hypernova explosion. Such an explosion will be so powerful, that even at the distance of over 1000 light years; Zeta Puppis will appear much brighter than even the full Moon.

Zeta Puppis is a fine example of a class O "runaway" star and is moving at a speed of over 100 kilometers a second. From the star’s movement, we can explicate the star’s place of origin, which is the molecular cloud of Vela, some 400 light years away from its current location.