May 29, 2013 | 3
Fifteen years ago the European Southern Observatory, a consortium of 15 member states, started scientific operations with the Very Large Telescope (VLT) on Cerro Paranal in the Chilean Atacama desert. The VLT is a beast of an observatory, to put it mildly.
Four 8.2 meter diameter mirrors are housed in domes that would put most single mirror observatories to shame, and they’re complemented by four 1.8 meter diameter movable telescopes that can be utilized for optical interferometry – a technique to significantly improve the resolving power of the observatory for bright objects.
Often though, visiting astronomers only make use of the individual 8.2 meter instruments – each on its own is an enormous light gathering bucket capable of detecting some of the faintest, and most distant, objects in our observable universe.
These great telescopes also have Mapuche names: Antu (The Sun), Kueyen (The Moon), Melipal (The Southern Cross), and Yepun (The evening star – Venus).
The above image of a stellar nursery was chosen to help celebrate the fifteen years of operation of the VLT observatory, and its extraordinary discoveries. The nursery has a rather dull name of IC 2944, but it’s a beautiful place. Intense light from young stars is ionizing hydrogen gas, stripping electrons from protons, and as the hydrogen ensnares new electrons it ejects photons of light with the characteristic red-pink glow that illuminates this place with the color of a spring rose.
But in among this glow are dark forms, like flocculated clumps of matter held in a watery suspension. These are usually known as Bok globules, or in this specific case they are called Thackeray’s Globules after South African astronomer David Thackerary who spotted them in IC 2944 in the 1950′s.
They’re the densest remnants of the gas and dust-rich nebula that once was. Eroded by the punishing ultraviolet light of nearby young massive stars they are being eaten away, evaporating and shrinking. Although it’s possible that these clumps might one day condense under their own weight to form new stars, there are no signs of this happening. The more probable fate is for them to be dissipated back into component atoms and molecules, adding to the surrounding rosy fog.
It may sound a little mournful, but this is all part of a cosmic cycle, one day perhaps the contents of these globules will end up helping give birth to another set of stars, and it’s a fitting image to celebrate the great VLT.
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