Vela Remnant
Here is a rather nice image of the north-eastern edge of the Vela supernova remnant probably near knot A. The Vela supernova exploded about 815 light years away (or 1500, or 2000 light years), about 11,000 years ago and is one of the closest supernova remnants to the Solar System. This image is created by combining radio observations made using ATCA and Parkes at a radio wavelength of 21cm (1420 MHz). Usually I would say that light colours corresponded to brighter parts of the image but I reckon the colour scale is reversed here, so dark means bright and light means dim. In case you were wondering, the centre of the supernova is below the bottom left of the image.
IMAGE: N. McClure-Griffiths, J. Dickey, B. Gaensler and A. Green.