[h=3]Mapping the Infrared Universe - The Entire WISE Sky[/h]This is a mosaic of the images covering the entire sky as observed by the Wide-field Infrared Survey Explorer (WISE), part of its All-Sky Data Release.
The sky can be thought of as a sphere that surrounds us in three dimensions. To make a map of the sky, astronomers project it into two dimensions. Many different methods can be used to project a spherical surface into a 2-D map. The projection used in this image of the sky, called Aitoff, takes the 3-D sky sphere and slices open one hemisphere, and then flattens the whole thing out into an oval shape.
In the mosaic, the Milky Way Galaxy runs horizontally across this map. The Milky Way is shaped like a disk and our solar system is located in that disk about two-thirds of the way out from the center. So we see the Milky Way as a band running through the sky. As we look toward the center of the galaxy, we are looking through more of the disk than when we are looking at large angles away from the center, and you can see a noticeable increase in stars (colored blue-green) toward the center of the image.
There are some artifacts worth noting in the image. For the image atlas, moving objects such as asteroids and comets were removed. However, some slower moving, bright objects did leave behind residuals. Residuals of the planets Saturn, Mars, and Jupiter are visible in this image as bright red spots off the plane of the galaxy at the 1:00, 2:00 and 7:00 positions, respectively. In addition, at several locations in the image there are small rectangular shaped features that result from the difficulty in matching background levels of individual atlas frames.
Three of the four wavelengths surveyed by WISE were used to create this image. The colors used in this image represent specific wavelengths of infrared light. Cyan (blue-green) represents light emitted predominantly from stars and galaxies at a wavelength of 3.4 microns. Green and red represent light mostly emitted by dust at 12 and 22 microns, respectively.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages, and operated WISE for NASA's Science Mission Directorate. The spacecraft was put into hibernation mode after it scanned the entire sky twice, completing its main objectives. Edward Wright is the principal investigator and is at UCLA. The mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
More information is online at NASA - WISE, http://wise.astro.ucla.edu and WISE - NASA Jet Propulsion Laboratory .
[h=3]Echoes of a Stellar Ending[/h]Over 11,000 years ago, a massive, supergiant star came to the end of its life. The star's core collapsed to form an incredibly dense ball of neutrons, and its exterior was blasted away in an immense release of energy astronomers call a supernova.
The light from this supernova first reached Earth from the direction of the constellation Cassiopeia around 1667 A.D. If anyone alive at the time saw it, they left no records. It is likely that large amounts of dust between the dying star and Earth dimmed the brightness of the explosion to the point that it was barely, if at all, visible to the unaided eye.
The remnant of this supernova was discovered in 1947 from its powerful radio emission. Listed as Cassiopeia A, it is one of the brightest radio sources in the whole sky. More recently, the Wide-field Infrared Survey Explorer (WISE), detected infrared echoes of the flash of light rippling outwards from the supernova.
In the image, the central bright cloud of dust is the blast wave moving through interstellar space heating up dust as it goes. The blast wave travels fast – at about six percent the speed of light. By the time WISE took this image, the blast wave has expanded out to about a distance of 21 light-years from the original explosion. The flash of light from the explosion, traveling at the speed of light, has covered well over 300 light-years. The orange-colored echoes further out from the central remnant are from interstellar dust that was heated by the supernova flash centuries after the original explosion.
The colors used in this image represent specific wavelengths of infrared light. Blue and cyan (blue-green) represent light emitted predominantly from stars at wavelengths of 3.4 and 4.6 microns. Green and red represent light mostly emitted by dust at 12 and 22 microns, respectively.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages, and operated WISE for NASA's Science Mission Directorate. The spacecraft was put into hibernation mode after it scanned the entire sky twice, completing its main objectives. Edward Wright is the principal investigator and is at UCLA. The mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
More information is online at NASA - WISE, http://wise.astro.ucla.edu and WISE - NASA Jet Propulsion Laboratory .
NASA unveiled a new atlas and catalog of the entire infrared sky today showing more than a half billion stars, galaxies and other objects captured by the Wide-field Infrared Survey Explorer (WISE) mission.
"Today, WISE delivers the fruit of 14 years of effort to the astronomical community," said Edward Wright, WISE principal investigator at UCLA, who first began working on the mission with other team members in 1998.
WISE launched Dec. 14, 2009, and mapped the entire sky in 2010 with vastly better sensitivity than its predecessors. It collected more than 2.7 million images taken at four infrared wavelengths of light, capturing everything from nearby asteroids to distant galaxies. Since then, the team has been processing more than 15 trillion bytes of returned data. A preliminary release of WISE data, covering the first half of the sky surveyed, was made last April.
The WISE catalog of the entire sky meets the mission's fundamental objective. The individual WISE exposures have been combined into an atlas of more than 18,000 images covering the sky and a catalog listing the infrared properties of more than 560 million individual objects found in the images. Most of the objects are stars and galaxies, with roughly equal numbers of each. Many of them have never been seen before.
WISE observations have led to numerous discoveries, including the elusive, coolest class of stars. Astronomers hunted for these failed stars, called "Y-dwarfs," for more than a decade. Because they have been cooling since their formation, they don't shine in visible light and could not be spotted until WISE mapped the sky with its infrared vision.
WISE also took a poll of near-Earth asteroids, finding there are significantly fewer mid-size objects than previously thought. It also determined NASA has found more than 90 percent of the largest near-Earth asteroids.
Other discoveries were unexpected. WISE found the first known "Trojan" asteroid to share the same orbital path around the sun as Earth. One of the images released today shows a surprising view of an "echo" of infrared light surrounding an exploded star. The echo was etched in the clouds of gas and dust when the flash of light from the supernova explosion heated surrounding clouds. At least 100 papers on the results from the WISE survey already have been published. More discoveries are expected now that astronomers have access to the whole sky as seen by the spacecraft.
"With the release of the all-sky catalog and atlas, WISE joins the pantheon of great sky surveys that have led to many remarkable discoveries about the universe," said Roc Cutri, who leads the WISE data processing and archiving effort at the Infrared and Processing Analysis Center at the California Institute of Technology in Pasadena. "It will be exciting and rewarding to see the innovative ways the science and educational communities will use WISE in their studies now that they have the data at their fingertips."
NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., manages and operates WISE for NASA's Science Mission Directorate in Washington. The mission was competitively selected under NASA's Explorers Program, which is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah, and the spacecraft was built by Ball Aerospace and Technologies Corp., in Boulder, Colo. Science operations, data processing and archiving take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
For a collection of WISE images released to date, visit: WISE - Multimedia Gallery: Images
An introduction and quick guide to accessing the WISE all-sky archive for astronomers is online at: WISE All-Sky Data Release
Instructions for technically minded individuals wanting to try their hand at using the archive are at: WISE - Multimedia Gallery: WISE Image Data Service
For more information about WISE, visit: NASA - WISE, http://wise.astro.ucla.edu and WISE - NASA Jet Propulsion Laboratory .
NASA - NASA Releases New WISE Mission Catalog of Entire Infrared Sky
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