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jueves, 15 de marzo de 2012

Astronomy: NASA Releases New WISE Mission Catalog Of Entire Infrared Sky

Hi My Friends: A VUELO DE UN QUINDE EL BLOG., 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.

March 14, 2012 -

Mapping the Infrared Universe: The Entire WISE Sky
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 is called Aitoff, named after the geographer who invented it. It takes the 3-D sky sphere and slices open one hemisphere, and then flattens the whole thing out into an oval shape.
Any projection creates distortions, so people tend to use a particular projection type based on where in the resulting map the distortions are minimal. This map is centered on the Milky Way Galaxy. The plane of the Galaxy runs along the equator, and the center of the Galaxy is at the center of the map, where projection distortions are minimal. The distortions are most pronounced at the edges of the map. The right and left edges of this oval shape are the same location in the sky. A second projection of this image is also available, called equirectangular. This method projects the sky into a rectangular shape with Cartesian coordinates, and is useful for planetariums that may wish to display the image on their domes.
In this mosaic, the Milky Way Galaxy runs horizontally across this map. The Milky Way is shaped like a disk and the 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.
With the exception of a few Solar System objects, all of the celestial bodies highlighted in previous featured images from WISE are visible in this map. The annotated version of this map shows the locations of about half of the featured images (the rest were omitted for clarity). Clicking on the name of the object in the annotated map above will open a new browser window showing the featured image for that object.
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.
Image Credit: NASA/JPL-Caltech/WISE Team

NASA Releases New WISE Mission Catalog Of Entire Infrared Sky

WASHINGTON -- 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:
http://wise.ssl.berkeley.edu/gallery_images.html
An introduction and quick guide to accessing the WISE all-sky archive for astronomers is online at:
http://wise2.ipac.caltech.edu/docs/release/allsky/
For more information about WISE,
visit:
http://www.nasa.gov/wise
Guillermo Gonzalo Sánchez Achutegui
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