Chandra X-ray Image of Cassiopeia A
Cassiopeia A (Cas A) is a 300-year-old supernova remnant created by the explosion of a massive star. Chandra shows hot gases at about 10 million degrees Celsius. This hot gas was created when ejected material from the supernova smashed into surrounding gas and dust at speeds of about ten million miles per hour. The turquoise dot at the center of the shell may be a neutron star created during the supernova. Blue Chandra data were acquired using broadband X-rays (low through high energies); green Chandra data correspond only to intermediate energy X-rays
(Credit: NASA/CXC/SAO)

Spitzer Infrared Image of Cassiopeia A
The Spitzer Space Telescope's data of the Cassiopeia A supernova remnant are from the telescope's 24-micron detector. Spitzer reveals warm dust in the outer shell with temperatures of about 26 degrees Celsius (50 degrees Fahrenheit). A comparison of the infrared and X-ray images of Cas A should enable astronomers to better understand how relatively cool dust grains can coexist in the superhot gas that produces the X-rays. It should also help to determine whether most of the dust in the supernova remnant came from the massive star before it exploded, or from the rapidly expanding supernova ejecta.
(Credit:NASA/JPL-Caltech/Steward/O.Krause et al.)

Hubble Optical Image of Cassiopeia A
The Hubble Space Telescope's data were taken using a 900 nanometer-wavelength filter. The optical image brings out the delicate filamentary structures of warmer (10,000 Celsius) gas in the Cassiopeia A supernova remnant.
(Credit: NASA/STScI)

Composite Image with Scale Bar

Scalebar: 2 arcmin
(Credit: X-ray: NASA/CXC/SAO; Optical: NASA/STScI; Infrared: NASA/JPL-Caltech/Steward/O.Krause et al.)