The
Bayer designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek alphabet, Greek or Latin letter followed by the genitive case, genitive form of its parent constellation's Latin name. The original list of Bayer design ...
θ Orionis (Theta Orionis) is shared by several astronomical objects, located near
RA DEC :
*
θ1 Orionis (41 Orionis), the Trapezium Cluster, an open star cluster, the ''Orion OB Association 1d''
**
θ1 Orionis A (41 Orionis A, HD 37020, V1016 Orionis), a trinary star system
**
θ1 Orionis B (41 Orionis B, HD 37021), a quintet star system
*** θ
1 Orionis B West (COUP 766, MAX 97), an astronomical X-ray source
*** θ
1 Orionis B East (COUP 778, MAX 101), an astronomical X-ray source
**
θ1 Orionis C (41 Orionis C, HD 37022), a binary star system
**
θ1 Orionis D (41 Orionis D, HD 37023), a B0.5Vp variable star
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θ1 Orionis E (COUP 732), a spectroscopic binary star system
**
θ1 Orionis F, a B8 variable star at 11th magnitude with a companion
**
θ1 Orionis G (COUP 826, MAX 116), a young stellar object
**
θ1 Orionis H (COUP 746, MAX 87), a young stellar object
*
θ2 Orionis (43 Orionis)
** θ
2 Orionis A (43 Orionis, HD 37041), a spectroscopic trinary
** θ
2 Orionis B (HD 37042), a B1V variable star
** θ
2 Orionis C (HD 37062), a binary star system
The various components are spread over several
arc-minute
A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...
s in and near the
Orion Nebula
The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula in the Milky Way situated south of Orion's Belt in the Orion (constellation), constellation of Orion, and is known as the middle "star" in the "sword" of Orion. It ...
.
{{Set index article , astronomical objects
Orionis, Theta
Orion (constellation)