This infrared image of the constellation of Chameleon was made from a single 12.5 x 12.5 degree field of the Infrared Astronomical Satellite (IRAS) Sky Survey Atlas. It is near the South Celestial Pole and is dominated by the emission of infrared cirrus. The cirrus consists of microscopic dust grains distributed throughout the neutral interstellar medium of our Galaxy. The grains are heated by the interstellar radiation field (the ensemble starlight of the Galaxy) and re-radiate at the mid- and far-infrared wavelength detected by IRAS. The image is a composite of 12 micron (coded blue), 25micron (coded green) and 60 micron (coded red) wavelengths. Stars are brighter at 12 micron and appear as blue dots in the picture.
The IRAS Sky Survey Atlas (ISSA) is the latest image product to come from the reprocessing of the IRAS data. Improved calibration and destriping methods reveal low surface brightness structure not seen in other IRAS products.
INFRARED PROCESSING AND ANALYSIS CENTER