Friday, January 2, 2009
Orion Nebula Reveals Thousands of Stars
New image from NASA's Spitzer and Hubble Space Telescopes looks more like an abstract painting than a cosmic snapshot. The magnificent masterpiece shows the Orion nebula in an explosion of infrared, ultraviolet and visible-light colors. It was "painted" by hundreds of baby stars on a canvas of gas and dust, with intense ultraviolet light and strong stellar winds as brushes.
At the heart of the artwork is a set of four monstrously massive stars, collectively called the Trapezium. These behemoths are approximately 100,000 times brighter than our sun. Their community can be identified as the yellow smudge near the center of the composite.
The swirls of green were revealed by Hubble's ultraviolet and visible-light detectors. They are hydrogen and sulfur gases heated by intense ultraviolet radiation from the Trapezium's stars.
Wisps of red, also detected by Spitzer, indicate infrared light from illuminated clouds containing carbon-rich molecules called polycyclic aromatic hydrocarbons. On Earth, polycyclic aromatic hydrocarbons are found on burnt toast and in automobile exhaust.
Additional stars in Orion are sprinkled throughout the image in a rainbow of colors. Spitzer exposed infant stars deeply embedded in a cocoon of dust and gas (orange-yellow dots). Hubble found less embedded stars (specks of green) and stars in the foreground (blue). Stellar winds from clusters of newborn stars scattered throughout the cloud etched all of the well-defined ridges and cavities.
Located 1,500 light-years away from Earth, the Orion nebula is the brightest star in the sword of the hunter constellation. The cosmic cloud is also our closest massive star-formation factory, and astronomers suspect that it contains about 1,000 young stars.
The Orion constellation can be seen in the fall and winter night skies from northern latitudes. The constellation's nebula is invisible to the unaided eye, but can be resolved with binoculars or small telescopes.
This image is a false-color composite, in which light detected at wavelengths of 0.43, 0.50, and 0.53 microns is blue. Light with wavelengths of 0.6, 0.65, and 0.91 microns is green. Light of 3.6 microns is orange, and 8-micron light is red.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. The Space Telescope Science Institute in Baltimore conducts Hubble science operations. The Institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc., Washington
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