The Edge of Space
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|Richard Hook||June 21st 2012|
European Southern Obervatory
|VLT image of NGC 6537 (credit: ESO)|
Deep in the Milky Way in the constellation of Scorpius (The Scorpion) lies the War and Peace Nebula, or NGC 6357, a region of space where new stars are being born of chaotic clouds of gas and dust. The name, which has no link to Tolstoy's great novel, was given to this object by scientists working on the Midcourse Space Experiment. They noted that the bright, western part of the nebula resembled a dove, while the eastern part looked like a skull in their infrared images. Unfortunately, this effect cannot be seen in the visible-light image presented here.
NGC 6357, also occasionally nicknamed the Lobster Nebula, was first recorded visually by John Herschel in 1837, but he only recorded the brightest central parts. The full scale of this huge nebula was only seen in photographs much later, and the outer parts of this vast nebula have now been imaged by ESO's Very Large Telescope (VLT).
The new picture shows a broad river of dust across the centre that absorbs the light from more distant objects. To the right there is a small cluster of brilliant blue-white young stars that have formed from the gas. These are probably only a few million years old, very young by stellar standards. The intense ultraviolet radiation streaming out from these stars is hollowing out a cavity in the surrounding gas and dust and sculpting it in strange ways.
The whole image is covered with dark trails of cosmic dust, but some of the most fascinating dark features appear at the lower right and on the right hand edge of the picture. Here the radiation from the bright young stars has created curious elephant trunk columns, similar to the famous “Pillars of Creation” in the Eagle Nebula. Cosmic dust, which is much finer than the more familiar domestic variety, more closely resembles smoke and consists mostly of tiny particles of silicates, graphite, and water ice that were produced and expelled into space by earlier generations of stars.
The bright central part of NGC 6357 contains a cluster of high-mass stars whose inhabitants are among the brightest in our galaxy. This inner region, not seen in this new picture, has been much studied and imaged by the NASA/ESA Hubble Space Telescope. But this new picture—of a section of the object not yet targeted by Hubble—shows that even the less well known outer parts of this nursery contain fascinating structures that can be revealed by the VLT.
This article is adapted from EurekAlert.