Infrared dark cloud

An infrared dark cloud (IRDC) is a cold, dense region of a giant molecular cloud. They can be seen in silhouette against the bright diffuse mid-infrared emission from the galactic plane.[1][2]

Cepheus B
Composite image showing young stars in and around molecular cloud Cepheus B.
Carina Nebula in infrared light (captured by the Hubble Space Telescope)
Eagle nebula pillars
Star formation


Infrared dark clouds have only been recently discovered in 1996 using the ISO [3] and therefore are in need of further research.[4]


Astronomers believe that they represent the earliest stage in the formation of high-mass stars [5] and are therefore of great importance for understanding the star formation process as a whole.[6]

Statistics and Mass


See also


  1. ^
  2. ^
  3. ^ "Archived copy". Archived from the original on 2011-01-01. Retrieved 2010-12-04.CS1 maint: Archived copy as title (link)
  4. ^ Frieswijk, W. W. F.; Shipman, R. F. (2010). "Searching for dark clouds in the outer galactic plane. I. A statistical approach for identifying extended red(dened) regions in 2MASS". Astronomy and Astrophysics. 515: 51. arXiv:1005.4955. Bibcode:2010A&A...515A..51F. doi:10.1051/0004-6361/200913000.
  5. ^
  6. ^
  7. ^
List of astronomy acronyms

This is a compilation of initialisms and acronyms commonly used in astronomy. Most are drawn from professional astronomy, and are used quite frequently in scientific publications. A few are frequently used by the general public or by amateur astronomers.

The acronyms listed below were placed into one or more of these categories:

Astrophysics terminology – physics-related acronyms

Catalog – collections of tabulated scientific data

Communications network – any network that functions primarily to communicate with spacecraft rather than performing astronomy

Data – astrophysical data not associated with any single catalog or observing program

Celestial object – acronyms for natural objects in space and for adjectives applied to objects in space

Instrumentation – telescope and other spacecraft equipment, particularly detectors such as imagers and spectrometers

Meeting – meetings that are not named after organizations

Observing program – astronomical programs, often surveys, performed by one or more individuals; may include the groups that perform surveys

Organization – any large private organization, government organization, or company

Person – individual people

Publication – magazines, scientific journals, and similar astronomy-related publications

Software – software excluding catalogued data (which is categorized as "catalog") and scientific images

Spacecraft – any spacecraft except space telescopes

Telescope – ground-based and space telescopes; organizations that operate telescopes (for example, the National Optical Astronomy Observatory (NOAO)) are listed under "organization"

List of infrared articles

This is a list of infrared topics.

Outline of astronomy

The following outline is provided as an overview of and topical guide to astronomy:

Astronomy – studies the universe beyond Earth, including its formation and development, and the evolution, physics, chemistry, meteorology, and motion of celestial objects (such as galaxies, planets, etc.) and phenomena that originate outside the atmosphere of Earth (such as the cosmic background radiation).

Serpens-Aquila Rift

The Serpens-Aquila Rift (also known as the Aquila Rift) is a region of the sky in the constellations Aquila, Serpens Cauda, and eastern Ophiuchus containing dark interstellar clouds. The region forms part of the Great Rift, a dark band that passes through the middle of the plane of the Milky Way Galaxy. The clouds that form this structure are called "molecular clouds", constituting a phase of the interstellar medium which is cold and dense enough for molecules to form, particularly molecular hydrogen (H2). These clouds are opaque to light in the optical part of the spectrum due to the presence of interstellar dust grains mixed with the gaseous component of the clouds. Therefore, the clouds in the Serpens-Aquila Rift block light from background stars in the disk of the Galaxy, forming the dark rift. The complex is located in a direction towards the inner Galaxy, where molecular clouds are common, so it is possible that not all components of the rift are at the same distance and physically associated with each other.Several star-forming regions are projected in (or near) the direction of the Serpens-Aquila Rift, including Westerhout 40 (W40), Serpens Main, Serpens south, Serpens NH3, and MWC297/Sh2-62.

Westerhout 40

Westerhout 40 or W40 (also designated Sharpless 64, Sh2-64, or RCW 174) is a star-forming region in our galaxy located in the constellation Serpens Cauda. In this region, interstellar gas forming a diffuse nebula surrounds a cluster of several hundred new-born stars. The distance to W40 is 436±9 pc (1420±30 light-years), making it one of the closest sites of formation of high-mass O- and B-type stars. The Ionizing radiation from the massive OB stars has created an H II region, which has an hour-glass morphology.Dust from the molecular cloud in which W40 formed obscures the nebula, rendering W40 difficult to observe at visible wavelengths of light. Thus, X-ray, infrared, and radio observations have been used to see through the molecular cloud to study the star-formation processes going on within.W40 appears near to several other star-forming regions in the sky, including an infrared dark cloud designated Serpens South and a young stellar cluster designated the Serpens Main Cluster. Similar distances measured for these three star-forming regions suggests that they are near to each other and part of the same larger-scale collection of clouds known as the Serpens Molecular Cloud.

Star systems
Related articles

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