Pillars of light: two views of the formation of stars from deep space

One of the most striking images captured by the Hubble Space Telescope is pictured below, the "pillars of creation" located in…

One of the most striking images captured by the Hubble Space Telescope is pictured below, the "pillars of creation" located in the Eagle Nebula. Originally taken in 1995 it showed three vast columns of gas and dust, the longest about a light year in length.

The nebula is a nearby star-forming region about 7,000 light years away in the constellation Serpens. Astronomers knew that infant stars were being formed within the columns but as the image was taken using visible light they were obscured.

Now a new image taken by a different telescope looking at infra-red wavelengths has revealed these young stars as they develop. The image on the left was taken by the 8.2 metre ANTU telescope at the European Southern Observatory's Paranal facility and takes much of the dust out of the picture.

The three pillars remain just visible in the Paranal image. Two of the three are seen to have very young, relatively massive stars in their tips. Less clear to a casual observer but apparent to an astronomer are the dozen or so less massive young stars dotted along the lengths of the pillars. These are associated with a phenomenon called EGGs and first seen in the Hubble view of the Eagle Nebula. The dust and hydrogen gas that form the pillars are being sculpted by ultraviolet light given off by very hot, massive stars located out of sight off the top edge of the Hubble image.

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The ultraviolet rays erode away the pillars in a process called "photoevaporation", leaving behind small globules of even denser gas within the columns. These globules, called EGGs for Evaporating Gaseous Globules, are actually embryonic stars. The Paranal image reveals them scattered over the surface of the pillars. The Paranal Observatory is located at the top of a 2,635-metre-high mountain in the Atacama Desert in northern Chile. It is the driest place on earth and very remote, making it ideal for space observations.

Dick Ahlstrom

Dick Ahlstrom

Dick Ahlstrom, a contributor to The Irish Times, is the newspaper's former Science Editor.