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New view of
North America Nebula

DR EMILY BALDWIN
ASTRONOMY NOW
Posted: 11 February 2011


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More than 2,000 candidate stars have been detected in the North America Nebula thanks to the infrared eyes of the Spitzer Space Telescope.

Previously only 200 young stars were known to exist in the nebula – which takes its name from the shape of the continent of North America, complete with the Gulf of Mexico – because newborn stars are swathed in blankets of dust that are hidden in visible light images. Thanks to Spitzer's penetrating infrared eyes, it can pierce these dusty cloaks to reveal the locations of new star-forming regions.


The changing face of the North America Nebula, here seen in visible light (top left), visible and infrared (top right), infrared (bottom left) and infrared with multiband imaging (bottom right). Dust clouds in the visible image become transparent in Spitzer's infrared views. Image: NASA/JPL-Caltech/L. Rebull (SSC/Caltech).

“One of the things that makes me so excited about this image is how different it is from the visible image, and how much more we can see in the infrared than in the visible,” says Luisa Rebull of NASA’s Spitzer Science Center, and lead author of a paper about the observations, which will appear in the Astrophysical Journal Supplement Series. “The Spitzer image reveals a wealth of detail about the dust and the young stars here.”

As a star forms inside a collapsing ball of gas and dust, material flattens out into a disc that spins around the forming star, with jets of material bursting out above and below the disc. Planets may form within the dusty disc before it disperses. Examples of all stages of a young star's life can be tracked in Spitzer's view.


The latest view of the North America Nebula from Spitzer, which contains data from both its infrared array camera and multiband imaging photometer. Light with a wavelength of 3.6 microns has been colour-coded blue; 4.5-micron light is blue-green; 5.8-micron and 8.0-micron light are green; and 24-micron light is red. Image: NASA/JPL-Caltech/L. Rebull (SSC/Caltech).

“This is a really busy area to image, with stars everywhere, from the North America complex itself, as well as in front of and behind the region,” says Rebull. “We refer to the stars that are not associated with the region as contamination. With Spitzer, we can easily sort this contamination out and clearly distinguish between the young stars in the complex and the older ones that are unrelated.”

A group of massive stars is thought to be powering the nebula, but as yet remain unidentified. The new Spitzer images hint that these 'missing' stars could be lurking behind the Gulf of Mexico portion of the nebula, their illumination spilling out from behind the dark clouds there. Further observations will help solve this mystery, as well as refining the distance to the nebula itself, which is currently estimated as around 1,800 light years from Earth.

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From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.
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Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.
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3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!
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