August 20, 2014
ESO Telescope Captures Images Of Two Regions Of Star Formation
redOrbit Staff & Wire Reports - Your Universe Online
The Wide Field Imager at the ESO’s La Silla Observatory in Chile has captured new images of two dramatic regions of star formation in the southern Milky Way, one of which features a Wolf–Rayet multiple star system.
Wolf-Rayet stars, the ESO explains, are at an advanced stage of stellar evolution and begin with a mass approximately 20 times that of the sun. However, despite their massive size, they shed a considerable amount of matter due to intense stellar winds that eject the stars’ surface material into space.
One of these Wolf–Rayet multiple star systems, known as HD 97950, rests at the heart of one of the regions imaged by the La Silla Observatory. That area, known as star cluster NGC 3603, is a very active area of star formation located roughly 20,000 light-years away in the Carina–Sagittarius spiral arm of the Milky Way galaxy.
According to the ESO, NGC 3603 is an extremely bright star cluster that is “famed for having the highest concentration of massive stars that have been discovered in our galaxy so far.” While stars are typically born in dark, dusty regions of space and are hidden from view, those newly-formed stars gradually begin shining, clearing away the surrounding cocoons of material and creating glowing clouds as they become visible.
Those clouds are known as Hill regions, and the agency explains that they shine as the result of the interplay between the ultraviolet radiation given off by the brilliant hot young stars and the surrounding hydrogen gas clouds. Hill regions can measure up to several hundred light-years in diameter, and the ESO said the one surrounding this newly-imaged region of star formation happens to be the most massive in our galaxy.
NGC 3603 was first discovered in March 1834 by John Herschel during a three-year expedition to survey the southern skies from Cape Town, South Africa. Herschel “described it as a remarkable object and thought that it might be a globular star cluster,” the ESO said, but future research revealed that it is actually a young open cluster.
Herschel was also responsible for discovering the other object captured by the Wide Field Imager, a collection of glowing gas clouds identified as NGC 3576. Discovered in 1834, NGC 3576 is only about half as far from Earth as NGC 3603 (9000 light-years away) and can also be found in the Milky Way’s Carina–Sagittarius spiral arm.
“NGC 3576 is notable for two huge curved objects resembling the curled horns of a ram,” the ESO said. “These odd filaments are the result of stellar winds from the hot, young stars within the central regions of the nebula, which have blown the dust and gas outwards across a hundred light-years.”
“Two dark silhouetted areas known as Bok globules are also visible in this vast complex of nebulae. These black clouds near the top of the nebula also offer potential sites for the future formation of new stars,” the intergovernmental astronomy organization, which also operates the Very Large Telescope in northern Chile, added.
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