The Infrared Helix (Expanded View)
August 27, 2007
The Helix Nebula, which is composed of gaseous shells and disks puffed out by a dying sunlike star, exhibits complex structure on the smallest visible scales. In this new image from NASA's Spitzer Space Telescope, infrared light at wavelengths of 3.2, 4.5, and 8.0 microns has been colored blue, green, and red (respectively). The "cometary knots" show blue-green heads due to excitation of their molecular material from shocks or ultraviolet radiation. The tails of the cometary knots appear redder due to being shielded from the central star's ultraviolet radiation and wind by the heads of the knots.
Topics: Infrared imaging, Electromagnetic spectrum, Planetary nebulae, Technology Internet, Spitzer Space Telescope, Infrared, Ultraviolet, Helix Nebula, Aquarius constellation, Radiation