Alnitak is the eastern star of Orion’s Belt, a blue-white supergiant with companions, whose light helps make the nearby Flame Nebula glow.
At a glance
| type | blue-white supergiant (class B) |
|---|---|
| distance from the Sun | 1,260 light-years (387 pc) |
| its light left it | 1,260 years ago |
| luminosity | 250,000 × the Sun |
| radius | 20 × the Sun |
| surface temperature | 29,500 K |
| constellation | Orion (Hunter) |
Read off the piece’s own catalogue, the same values it draws with.
About Alnitak
Alnitak is a system of hot, massive stars, the brightest of them a blue-white supergiant enormously more luminous than the Sun. The main star has a close companion detected in its spectrum and by interferometry, and a fainter blue star that a telescope separates.
On the sky it lies beside the Flame Nebula, NGC 2024, a cloud of gas lit and ionised by ultraviolet light, and the dark Horsehead Nebula is just to the south. These clouds belong to the great star-forming complex in Orion, of which the belt stars are young, short-lived members.
What you see in the piece
With HUMAN EYE on it is the left-hand star of the belt as seen from the north, blue-white. Fly out towards Orion and the belt stars, which look like a neat row from Earth, separate in depth.
Questions
Which star is Alnitak in Orion’s Belt?
Alnitak is the easternmost of the three belt stars, alongside Alnilam and Mintaka. It is 1,260 light-years (387 pc) from the Sun.