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Embedded cluster

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X-ray view of Orion showing the Trapezium embedded cluster.

Embedded stellar clusters or simply embedded clusters (EC) are groupings of stars that are still encased in its progenitor molecular cloud. [1] They are often areas of active star formation giving rises to a collection of stellar objects which share a similar age and material makeup. Due to the dense material that surrounds the stars, they are impervious to optical observation but reveal themselves in other spectra such as in the near infrared and X-rays.

Often for these spectra, like the older open cluster cousins for the optical, they may be detected as stellar enhancements above expected galactic background stellar counts [2]. Other-times such an approach would fail, as the number of background stars shielded from view by the surrounding dust and gas would cancel out any enhancement. This is particularly prevalent towards the galactic bulge.

The sizes of stellar objects born in embedded clusters are thought to follow the initial mass function. There are therefore ideal places to study massive star formation.

Although many embedded stellar clusters are know to exist, few have specified names. Below named object believed to exist in its vicinity are labelled.

  1. Trapezium cluster
  2. Rho_Ophiuchi_cloud_complex
  3. IRAS 22551+6621
  4. IRAS 22172+5549
  5. IRAS 00070+5549
  1. ^ "Embedded clusters in molecular clouds". Annual Review of Astronomy and Astrophysics. 41: 57–115. 2004.
  2. ^ A 2MASS study of candidate precursors to UCHII regions (Thesis). {{cite thesis}}: |access-date= requires |url= (help)