X-ray image of the Cygnus Loop

An X-ray picture of the Cygnus Loop, recorded with an imaging X-ray telescope, is presented. The results are highly suggestive of a limb-brightened shell of hot gas which results from the expansion of a blast wave into the interstellar medium. Spatial structure is clearly evident on scale sizes down to about 1/4 deg, a likely indication of the inhomogeneities in the interstellar medium. No evidence is found for any discrete X-ray-emitting remnant of the original supernova explosion.