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Clouds of interstellar dust

Interstellar gas and dust, NGC 7023

 Automatic translationAutomatic translation Category: nebulas
Updated June 01, 2013

These clouds of interstellar dust and gas have blossomed to 1 400 light years from us, the stars located in the heart of the fertile fields of the constellation of the northern hemisphere: Cepheus.
Sometimes called the Iris Nebula NGC 7023 and cataloged, it is not the only diffuse nebula in the sky to evoke an image of flowers, but the Iris Nebula, not only evokes the flower opening its petals cosmic observers, but shows a more impressive symmetry.
Around the nebula, and other forms of dark clouds just as amazing are also present and obscure the clouds of dust and cold molecular gas.
Within the Iris Nebula, the dust surrounding a hot material, which is a massive young star still being formed.
The dominant color of the bright reflection nebula is blue, which is a characteristic of dust grains reflecting starlight.
The bubbles of cosmic dust have a low red glow luminescent image reflected by the dust grains that make the ultraviolet radiation of red light of the stars hidden.


The infrared observations indicate that this diffuse nebula may contain complex carbon molecules.
These molecules known to UPAH (Understanding Polycyclic Aromatic Hydrocarbons) which are organic molecules composed of carbon and hydrogen.
This remarkable view of the Iris Nebula, is located on a vast area of over 30 light years.

Note: reflection nebulae are the same as dark nebulae, however, they reflect in part the light of a nearby star.

Image The Iris Nebula (NGC 7023) is a cloud of interstellar dust and gas located in the constellation Cepheus. Its size is 8x10 minutes of arc. Credit & Copyright: Alvin Jeng (

 interstellar dust clouds

Interstellar gas and dust, NGC 6726


In this area very rich in stars, spreads a dark, elongated clouds of cosmic dust, visible in this vast telescopic view showing the northern border of the constellation Corona Australis.
These clouds are probably located within 500 light years away and block the light from distant stars from the Milky Way.
The bulk of the cloud of black dust, measuring about 8 light-years long.
At the right end of the dust cloud, the group is the beautiful reflection nebula cataloged NGC 6726, 6727, 6729 and IC 4812.
The characteristic blue color, reflected by the cosmic dust is produced by hot stars located inside the cloud.


The tiny yellowish nebula in the lower right of the image is NGC 6729, it houses the young variable star R Corona Australis in the constellation.
The beautiful globular star cluster NGC 6723 is at the upper right corner of the view.
While the nebula NGC 6723 appears to be part of this group, it is actually close to 30 000 light years, beyond the dust clouds of Corona Australis.

Image: In this picture you can see a great cloud of dust and a host of nebulae in the constellation Corona Australis. credit & Copyright: Andrey Oreshko

 interstellar dust clouds

Interstellar gas and dust, Dark River


On the left, at the edge of the image is the dark cloud of dust illuminated by the yellow light of the star Antares, a double star in the constellation Scorpio, the southern sky.
In the background, the entire length of the image, we see the central band of our Milky Way, which seems connected to Antares by streams of dust, known as Dark River.
Upper of the Dark River is a knot of dense dust. Node, the B44 is darker, down the image against.
The area of reflection blue, bottom left of the image, is known as the nebula IC 4605.
B44 and IC 4605 lies about 500 light-years away towards the constellation of Scorpio.


Note: Antares is a double star of Scorpio with the brightest component (α Scorpii Antares A or A) is a red supergiant at the end of life, a mass of 15.5 solar masses and a diameter 700 times than the Sun.
Antares is located about 600 light years and its apparent magnitude ranging from 0.9 to 1.8.

Image: The Dark River splits the image into two left with the super giant Antares. Credit & Copyright: Thomas V. Davis (

 nebula of dust
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