Though only some twelve times the Sun'sdiameter, this supergiantstar emits extraodinary levels of energy: it is some 9,000 times more intrinsically luminous than the Sun in visible light, and produces more than 150,000 times as much energy across the entire spectrum.
The easternmost of the three stars that make up
Orion's Belt, Alnitak is a binary. The primary is
an O-typesupergiant, one of the most luminous of
star-types, meaning that shines as brightly as
magnitude +1.7 despite being more than 700
light years away.
The sky around Alnitak is densely populated with nebulae. To the immediate east is the Flaming Tree Nebula, composed of branching lanes of dark dust against a glowing background, while to the south of the star the distinctive shape of the Horsehead Nebula can be seen. Between the two nebulae, southeastward from Alnitak, is a patch of blue-white light known as the Lump Star which, though appearing star-like, is in fact another nebula within the surrounding complex. Imagery provided by Aladin sky atlas
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