Nair al Saif — Double Star in Orion
HIP 26241; Iota Orionis; 44 Orionis
About Nair al Saif
Description
Nair al Saif is a hot blue star of spectral type O9III at magnitude 2.77 in Orion. Located about 1,300 light-years from Earth, it has a luminosity of roughly 68,000 times solar and is one of the few O-type stars visible to the naked eye. It lies at the tip of Orion's Sword, below the Great Orion Nebula.
Observing Tips
Nair al Saif is the bottom star of Orion's Sword, below the Orion Nebula (M42). It is a blue-white star marking the sword's tip. The surrounding area is rich in nebulosity visible in photographs. Best observed December through March.
History
The name Nair al Saif comes from the Arabic 'nayyir al-sayf,' meaning 'the bright one of the sword.' As an O-type star, it is one of the hottest and most massive stars visible to the naked eye. It illuminates the nearby nebula NGC 1980.
Fun Facts
Iota Ori is a trapezium-like multiple star system similar to the famous Trapezium in M42. Its extreme luminosity and temperature contribute to ionizing the surrounding interstellar medium in the Orion OB1 association.
Observe
1Physical Properties
2Position & Identifiers
3How easy to split?
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | Medium+ | Medium+ | Medium+ |
| 150 mm Newton 150mm Newt. | Easy | Easy | Easy |
| Celestron C8 (203 mm SCT) C8 203mm | Easy | Easy | Easy |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
Set a location in User Settings to see visibility data.
5Light Curve
6Multiple Star System Triple optical
Separation over time
Slow change over generations — observable in lifetime comparisons.
Measured from the WDS observational archive. No orbital solution has been derived — most likely the period is too long to fit an orbit to the available measurement arc.
Eyepiece View
A: 2.8 · B: 7.7 · Sep: 11.2″ · PA: 141° · N up, E right
Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 2.3″
Explore
8
Size Comparison
9
Compare Stars
10
Spectral Classification
11
Hertzsprung-Russell Diagram
12
Stellar Lifecycle
13
Blackbody Spectrum
14
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
15
Stellar Fusion
Discover
16Stellar Notes
17
Light Travel Time Machine
18
Relativistic Travel
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
Explore Nightbase
Related knowledge, tools, and stories — no observation planning required.
