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Herschel brings stars to life
DR EMILY BALDWIN ASTRONOMY NOW Posted: December 21, 2009

A previously unseen stellar nursery buried deep within the heart of the Eagle constellation is brought to life by ESA's Herschel Space Observatory.
A previously unseen star-forming region in the 1,000 light year distant constellation Aquila, the Eagle. Image: ESA and the SPIRE & PACS consortia, P. André (CEA Saclay) for the Gould’s Belt Key Programme Consortia.
The new image was taken on 24 October using Herschel's Photodetector Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE), and covers an area 65 light years across. It is so shrouded in dust that no previous infrared satellite has been capable of imaging it.
Herschel's new view of the dusty nursery reveals two bright regions where large newborn stars are lighting up hydrogen gas, while some 700 individual star-forming pods are estimated to exist in this field of view. Around 100 are protostars, stars in the final stages of formation but have yet to ignite nuclear fusion in their cores.
A region of the Virgo cluster; the left panel shows a region containing four galaxies in optical light, from the Sloan Digital Sky Survey, while the right panel shows the region as
seen by SPIRE at 250 microns.
"These results are extremely impressive and are an indication of the excellent science that Herschel, including SPIRE, will perform over the next few years," says Professor Keith Mason, Chief Executive of the Science and Technology Facilities Council (STFC), which provides the UK funding for Herschel. "We’re very proud of the technology and expertise that the UK has contributed to this groundbreaking mission.”
The image is made from the three SPIRE bands, with red, green and blue corresponding to 500 microns, 350 microns and 250 microns, respectively. Every fuzzy blob in this image is a very distant galaxy, seen as they were 3-10 billion years ago when the star formation was very widely spread throughout the Universe. This is the first time much of the Cosmic Infrared Background has been resolved into the individual galaxies.
Other newly released images include a region of the Virgo cluster, a large cluster of galaxies around 50 million light-years from our Galaxy; an area of sky called the “Great Observatory Origins Deep Survey” (GOODS), which has been observed by many telescopes at a range of wavelengths, and now by SPIRE in the far-infrared, and the detection of a previously known dwarf planet, MakeMake, which orbits the Sun out beyond Neptune.
Makemake is one of the coldest objects in the Solar System, and so very hard to detect. By taking images 44 hours apart and subtracting the “before” image from the “after” image, the background sky is removed. Makemake, having moved in the intervening time, appears twice in the resulting image: once as a “negative image” and again as a “positive image”.
"The Herschel Science Demonstration meeting is what the SPIRE team has been looking forward to since the start of the project more than a decade ago, and the results being presented are even better than we dared hope before launch," Professor Matt Griffin, SPIRE Principle Investigator, said, "Not only are the observatory and the instrument working very well, but it is already clear that in this unexplored region of the spectrum, the Universe is even more interesting than we thought."
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