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Lighting up a Dead Star's Layers
Ssc2006 19a

Credit: NASA/JPL-Caltech/L. Rudnick (University of Minnesota)

Observation • • ssc2006-19a


This image from NASA's Spitzer Space Telescope shows the scattered remains of an exploded star named Cassiopeia A. Spitzer's infrared detectors "picked" through these remains and found that much of the star's original layering had been preserved.

In this false-color image, the faint, blue glow surrounding the dead star is material that was energized by a shock wave, called the forward shock, which was created when the star blew up. The forward shock is now located at the outer edge of the blue glow. Stars are also seen in blue. Green, yellow and red primarily represent material that was ejected in the explosion and heated by a slower shock wave, called the reverse shock wave.

The picture was taken by Spitzer's infrared array camera and is a composite of 3.6-micron light (blue); 4.5-micron light (green); and 8.0-micron light (red).

About the Object

Cassiopeia ACas A3C461
Nebula > Type > Supernova Remnant
11,000 Light Years

Color Mapping

Band Wavelength Telescope
Infrared 3.6 µm Spitzer IRAC
Infrared 4.5 µm Spitzer IRAC
Infrared 8.0 µm Spitzer IRAC


Position ()
RA =23h 23m 26.7s
Dec = 58° 49' 13.9"
Field of View
0.0 x 0.0 arcminutes
North is up