WAZN (Beta Columbae). Though the second brightest star in Columba (the Dove), third magnitude (3.12) Beta Columbae takes third place in recognition after brighter third magnitude Phact (Alpha Col, 2.64) and the runaway star Mu Col. Otherwise an ordinary class K (K2) giant, it has three oddities that bring it to the table. The first is confusion over the name, which derives from the Arabic "al-wazn," meaning "the weight," the weight of WHAT not at all clear. Kunitzsch and Smart say that the term seems to apply to "one of a pair of stars." Which one is not clear either. The name has been related both to Alpha Centauri and to Delta Canis Majoris, and then also wound up with our Beta Columbae. The latter two stars are distinguished by spelling, Delta CMa known as Wezen, Beta Col as Wazn. At a distance of 86 light years, this calm, core- helium-fusing giant shines with the light of 53 Suns from its 4535 Kelvin surface, which leads to a smallish (for a giant) radius of 12 solar, a mass of about 1.7 solar, and an age of about two billion years. The rotation velocity is unknown, there is no X-ray emission, and there are no known companions. As the second of the oddities, what it does have is speed. Moving at a rather amazing 103 kilometers per second relative to the Sun (6 to 7 times normal), it is going almost as fast as runaway Mu Col, in this case showing it to be a visitor from another part of the Galaxy. Most such speedsters are passing through the Galaxy's disk from the extended halo and have the halo's low metal abundance. Enter the third oddity. Instead of a low metal content, Wazn's metal-to-hydrogen ratio is some 30 percent HIGHER than the Sun's. Nevertheless, for all the strangeness, Wazn, which started life as a relatively modest class A dwarf, will (like any other giant) before long lose its outer hydrogen envelope through a strong wind that will develop after the helium fuel is gone, and then expire as a relatively ordinary white dwarf -- though one with a lot of zip in it.
Written by Jim Kaler 3/09/07. Return to STARS.