Iota Orionis: A Runaway Star in Orion’s Sword

Iota Orionis is a star viewable with the naked eye. It lies in the constellation Orion and sits near the famous Orion Nebula. Traditionally, the star goes by the name Na’ir al Saif, which translates to “the Bright One of the Sword” in Arabic. As one of the hottest stars in Orion, Iota Orionis burns at an unimaginable 56,000 degrees Fahrenheit!

According to astronomer Jim Kaler, the star is a complex multiple star system. What’s more, Na’ir al Saif is apparently related to several other stars known as runaways from the region around the Orion Nebula. Jim Kaler describes the fascinating history of Iota Orionis in the following passage adapted from his webpage:

“Na’ir al Saif appears to be a ‘runaway star,’ kicked out of the Trapezium Cluster by a very close encounter between two binaries years ago, along with AE Aurigae and Mu Columbae. Two of the four stars were ejected, while the remaining two, instead of being evicted, stayed more or less behind in a highly eccentric embrace. Na’ir al Saif still lingers near the Orion Nebula, marking the place of the violent event. More violence is in store, as the star is fated to explode as a supernova.”

As one looks up at the night sky and observes how far apart Mu Columbae (in the Columba constellation) and AE Aurigae (in Auriga) are, it’s hard to believe these sister stars once lived together in Orion.

My Observations

With an outside temperature of 19F and a humidity of 93%, this New Year’s Eve is fridged. When 2021 started, we were hopeful the end of the pandemic was in sight. But unfortunately, a new version of the virus (called Omicron) seems to be spreading everywhere. The cold weather and growing cloud bank out will end my evening after this observation of Iota Orionis.

Iota Orionis is a stellar white amongst a pretty collection of other stars. A pair of equally bright white stars reside nearby (see my sketch). According to my sky charts, this pair belongs to Struve 747, but I’d like to revisit this area to be sure I’m not mistaken with this assessment as it’s a busy field of various magnitude stars.

It’s time to say goodbye to 2021. As I look at the scorching sun of Iota O. and this pretty starfield of young blue companion stars, I think of rebirth with hope and prayers for a better 2022.

Key Stats

Constellation	Orion
Best Viewing	Winter
Visual Magnitude	+2.8, +7
Absolute Visual Magnitude	-1.5
Distance from Earth	2300 ly
Separation	41.1″ | 29400 AU
Milky Way Location	Orion Spur
My Viewing Grade	A

Sources and Notes

Banner photo is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. It’s provided by Rawastrodata as credited here.

Sketch by Wayne McGraw

AKA: Nair al Saif, 44 Ori, Member of NGC 1980