This spectacular image was captured by the Wide Field Imager at the La Silla Observatory in Chile, and released today by the European Southern Observatory. To the right of the photograph is nebula NGC 3576. On the left is star cluster NGC3603, home to the Milky Way's highest known concentration of massive stars.
NGC 3603 is in an area of very active star formation. Stars are born in dark and dusty regions of space, largely hidden from view. But as the very young stars gradually start to shine and clear away their surrounding cocoons of material they become visible and create glowing clouds in the surrounding material, known as HII regions. HII regions shine because of the interaction of ultraviolet radiation given off by the brilliant hot young stars with the hydrogen gas clouds. HII regions can measure several hundred light-years in diameter, and the one surrounding NGC 3603 has the distinction of being the most massive in our galaxy.
The cluster was first observed by John Herschel on 14 March 1834 during his three-year expedition to systematically survey the southern skies from near Cape Town. He described it as a remarkable object and thought that it might be a globular star cluster. Future studies showed that it is not an old globular, but a young open cluster, one of the richest known.
NGC 3576, on the right of the image, also lies in the Carina–Sagittarius spiral arm of the Milky Way. But it is located only about 9000 light-years from Earth — much closer than NGC 3603, but appearing next to it in the sky.
This wide-field image, based on data from Digitized Sky Survey 2, shows the whole region around the cosmic factory NGC 3603, located about 20 000 light-years away. This region contains many star formation regions featuring huge clouds of glowing gas | Photo and Caption Credit: ESO/Digitized Sky Survey 2
This zoom sequence takes the viewer deep into the spectacular southern Milky Way in the constellation of Carina (The Keel). We see two regions where stars are forming, the very rich cluster NGC 3603 and its surroundings and the strange glowing gas clouds known as NGC 3576. The final detailed views come from images taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile | Photo and Caption Credit: ESO/Digitized Sky Survey 2