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This image, taken by OmegaCAM on the VLT Survey Telescope at Paranal Observatory, shows a section of the Ara OB1 stellar association. In the centre of the image is the young open cluster NGC 6193, and to the right is the emission nebula NGC 6188, illuminated by the ionizing radiation emitted by the brightest nearby stars.
FOUR THOUSAND LIGHT years from Earth, in the constellation Ara, big, bright stars are illuminating an incredible scene of creation and destruction. This is a stellar nursery, a place where stars are born, nurtured by the hydrogen in its glowing clouds of gas. Captured in visible light by the VLT Survey Telescope in Chile, this is the most detailed photo yet of this patch of sky, showing young stars so bright and energetic that they’re destroying the environment that gave birth to them—and giving rise to yet another generation of stars.
You can see about 30 of these bright, young stars in the middle of the image, which itself spans about 70 light years across. These stars are about a million years old—teenagers as far as stars are concerned. 100,000 times brighter than the sun (and up to about 50 times as massive), they’re bursting with ultraviolet light that turns some of their neighboring gas molecules into hot plasma—glowing in pinks, reds, and oranges. “It’s kind of cooking the surface of the molecular clouds,” says Nathan Smith, an astronomer at the University of Arizona.
The part that stays uncooked—the cold and dusty inner regions of the clouds, seen here in dark patches—is where a new generation of stars is forming, spurred on by the adolescents next door. “These newly born massive stars have a violent impact on their natal surroundings,” says Smith. They produce powerful streams of charged particles called stellar wind, which carves out a bubble in the surrounding gas clouds. The wind and UV radiation from the teenage stars pushes on the cold gas, pressurizing it just enough to make some of it collapse—igniting nuclear fusion, and creating new stars.
