Thanks to the superior sensitivity at the longest wavelength of infrared part of the electromagnetic spectrum, the Herschel Space Observatory unveiled a previously unseen stellar nursery, located within a dark could 1000 light years away in the constellation Aquila (the Eagle). No other infrared satellite could see the interior of this cloud through its dust shroud before.
The image (click here for high-resolution version) was taken on 24 October 2009 using two of Herschel’s instruments: the Photodetector Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE). The two bright regions are areas where large newborn stars are causing hydrogen gas to shine.
Some 700 newly-forming stars are estimated to be crowded into these colourful filaments of dust. The complex is part of a mysterious ring of stars called Gould’s Belt. Embedded within the dusty filaments are 700 condensations of dust and gas that will eventually become stars. Astronomers estimate that about 100 are protostars, celestial objects in the final stages of formation. Each one just needs to ignite nuclear fusion in its core to become a true star. The other 600 objects are insufficiently developed to be considered protostars, but these too will eventually become another generation of stars.
This cloud is part of Gould’s Belt, a giant ring of stars that circles the night sky – the Solar System just happens to lie near the center of the belt. For more than a hundred years, astronomers have puzzled over the origin of this ring, which is tilted to the Milky Way by 20º. The first to notice this unexpected alignment, in the mid-19th century, was England’s John Herschel, the son of William, after whom ESA’s Herschel telescope is named. But it was Boston-born Benjamin Gould who brought the ring to wider attention in 1874.