Iota Orionis
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Double star ι Orionis |
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | Orion | ||||||||||||||||||||
| Right ascension | 05 h 35 m 25.98 s | ||||||||||||||||||||
| declination | -05 ° 54 ′ 35.6 ″ | ||||||||||||||||||||
| Apparent brightness | 2.77 (2.76 to 2.79) mag | ||||||||||||||||||||
| Typing | |||||||||||||||||||||
| B − V color index | (−0.24) | ||||||||||||||||||||
| U − B color index | (−1.08) | ||||||||||||||||||||
| Spectral class | O9 III + B0.8IV / V | ||||||||||||||||||||
| Variable star type | HB | ||||||||||||||||||||
| Astrometry | |||||||||||||||||||||
| Radial velocity | (27.6 ± 0.3) km / s | ||||||||||||||||||||
| distance | 1,325 ly | ||||||||||||||||||||
| Physical Properties | |||||||||||||||||||||
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Other names and catalog entries |
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Nair Al Saif is the proper name of the star ι Orionis ( Iota Orionis , Arabic نير السيف, DMG Nair as-Saif 'The Light in the Sword') also known under the name Hatysa . The star is 5 ° south of the Orion Belt and 0.5 ° south of the Orion Nebula (M42). It is a double star that can be separated even in small telescopes with a +2.77 mag bright star of the spectral class O9III and a +6.9 mag bright companion of the spectral type B7. The companion is located at an angular distance of 11.3 "at a position angle of 141 degrees with respect to the main star. Nair Al Saif is approx. 1325 light years away from Earth ( Hipparcos database).
A third faint star can be seen in the eight-inch at a distance of about 50 ".