| |
 |
| Paper: |
The σ Orionis Cluster |
| Monograph: |
4, Handbook of Star Forming Regions:
Volume I, The Northern Sky |
| Page: |
732 |
| Authors: |
|
| Abstract: |
The σ Orionis cluster is the group of stars surrounding the high mass σ Ori stellar system. It is kinematically distinct from the Orion OB1a and OB1b associations, against which it is projected. The cluster could contain up to ∼700 stars and substellar mass objects, with a total mass of about 225 M⊙ within a radius of about 30 arcmin. The age is 2–3 million years. The distance, from main sequence fitting corrected for the sub-solar metallicity, is 420±30 pc. The mass function is similar to the field star mass function, and has been traced well into the planetary mass regime. The disk fraction is normal for its age. The cluster appears to be an older and less massive analog of the Orion Nebula Cluster. |
|
|
|
|
|
