Supernova Dust Factory in M74
Astronomers using NASA's Spitzer Space Telescope have spotted a "dust factory" thirty million light-years away in the spiral galaxy M74. The factory is located at the scene of a massive star's explosive death, or supernova.
While astronomers have suspected for years that supernovae could be producers of cosmic dust particles, the technology to confirm this suspicion has only recently become available.
The dust factory, also known as supernova SN 2003gd, is shown at the center of the two small insets from Spitzer's Infrared Array Camera (IRAC). A white arrow points to its exact location. The yellow-green dot shown in the July 2004 inset (top) shows that the source's temperature is warmer than the surrounding material. This is because newly formed dust within the supernova is just starting to cool. By January 2005, the dust had cooled and completely faded from IRAC's view. However, it was still detected in January 2005 by another instrument aboard Spitzer called the Multiband Imaging Photometer (MIPS). The MIPS image is not shown here.
The larger image to the right of the insets is the galaxy M74, as seen by Spitzer's Infrared Array Camera. The white box to the left of the galaxy's center identifies the location of the supernova remnant. In all the images, the blue dots represent hot gas and stars. The galaxy's cool dust is shown in red.
The images are infrared composites, in which 3.6-micron light is blue, 4.5-micron light is green, and 8-micron light is red.