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Thursday, February 16, 2012

The Closest Star Formation Regions Has Detected

The closest star formation regions has detected. Research collaboration between the Max-Planck-Institut für Radioastronomie (MPIfR), Onsala Space Observatory (OSO), ESO, using the telescope APEX (Atacama Pathfinder Experiment) with LABOCA camera, stating that the region located in the constellation of Taurus within 450 million light years of the earth.

Within this constellation, there is a cosmic dust filament (The Taurus Molecular Cloud) winding with length more than ten years of light. In it, the hidden number of new stars and dense clouds of gas on the verge of collapse are ready to form other new stars. The image  below shows two parts of a long, filamentary structure in this cloud, which are known as Barnard 211 (the upper-right) and Barnard 213 (the lower-left). Their names come from Edward Emerson Barnard’s photographic atlas of the “dark markings of the sky”, compiled in the early 20th century. In visible light, these regions appear as dark lanes, lacking in stars. Barnard correctly argued that this appearance was due to “obscuring matter in space”.

the taurus molecular cloud
The Taurus Molecular Cloud. (eso.org)

These dark markings are actually clouds of interstellar gas and dust grains. The dust grains — tiny particles similar to very fine soot and sand — absorb visible light, blocking our view of the rich star field behind the clouds. The Taurus Molecular Cloud is particularly dark at visible wavelengths, as it lacks the massive stars that illuminate the nebulae in other star-formation regions such as Orion (see for example eso1103). The dust grains themselves also emit a faint heat glow but, as they are extremely cold at around -260 degrees Celsius, their light can only be seen at wavelengths much longer than visible light, around one millimetre (see image eso1209b and the mouseover comparison eso1209ea to see how the millimetre-range view appears bright where the visible-light view appears dark and obscured).

These clouds of gas and dust are not merely an obstacle for astronomers wishing to observe the stars behind them. In fact, they are themselves the birthplaces of new stars. When the clouds collapse under their own gravity, they fragment into clumps. Within these clumps, dense cores may form, in which the hydrogen gas becomes dense and hot enough to start fusion reactions: a new star is born. The birth of the star is therefore surrounded by a cocoon of dense dust, blocking observations at visible wavelengths. This is why observations at longer wavelengths, such as the millimetre range, are essential for understanding the early stages of star formation.

Revealed the heat glow of the cosmic dust grains, are shown here in orange tones, and are superimposed on a visible light image of the region, which shows the rich background of stars. The bright star above the filament is φ Tauri, while the one partially visible at the left-hand edge of the image is HD 27482. Both stars are closer to us than the filament, and are not associated with it.

Observations show that Barnard 213 has already fragmented and formed dense cores — as illustrated by the bright knots of glowing dust — and star formation has already happened. However, Barnard 211 is in an earlier stage of its evolution; the collapse and fragmentation is still taking place, and will lead to star formation in the future. This region is therefore an excellent place for astronomers to study how Barnard’s “dark markings of the sky” play a crucial part in the lifecycle of stars.

This article has edited by author of threelas
Source: http://www.eso.org/public/news/eso1209/

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