Location of δ Orionis (circled), as shown in a conventional star chart, that is looking at the southern or overhead sky from northern latitudes. The star generally appears on the left in the Southern Hemisphere looking at the northern sky.
Mintaka is the westernmost of the three stars of Orion's belt. It is easily visible to the naked eye, one of the brightest stars in the sky, and has been known since antiquity.
The main component itself is triple: a class O9.5 bright giant and a class Bmain sequence star orbit every 5.73 days and exhibit shallow eclipses when the star dims about 0.2 magnitudes; and a B-class sub-giant is resolved 0.26" away. At the primary eclipse, the apparent magnitude (of the whole system) drops from 2.23 to 2.35, while it only drops to 2.29 at the secondary eclipse.
Mintaka C (alias B) HD36485
A well-noted seventh magnitude companion, HD 36485, is an unusual B-type main sequence star and itself a spectroscopic binary with a faint A-type companion in a 30-day orbit.
Mintaka B (14th magnitude star)
A 14th magnitude star is thought to be at the same distance, but it is not clear whether it is physically bound to the primary star and little is known about it.
Position of overall system and nomenclature issues
Mintaka is surrounded by a cluster of faint stars, possibly part of the cluster surrounding σ Ori.
The bright central, triple star of the system is δ Ori A. Its components are generally referred to by researchers as Aa1, Aa2, and Ab. HD 36485 is referred to as Mintaka (or δ Ori) C, and the closer fourteenth magnitude companion as δ Ori B. Confusingly, some catalogues list closely orbiting δ Ori Ab as component B or component D, and Simbad names that star as Delta Orionis B.
The distance derived from the Hipparcos satellite parallax is 212 ± 30 pc, while spectroscopic distances, comparisons to similar stars, and cluster membership all suggest a value more than double that. This type of unreconcilable discrepancy is not unique to Mintaka and the reasons for it have yet to be clarified.
Etymology and cultural significance
Mintaka was seen by astrologers as a portent of good fortune.
The three belt stars were collectively known by many names in many cultures. Arabic terms include Al Nijād 'the Belt', Al Nasak 'the Line', Al Alkāt 'the Golden Grains or Nuts' and, in modern Arabic, Al Mīzān al H•akk 'the Accurate Scale Beam'. In Chinese mythology they were also known as the Weighing Beam.
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