HAlpha image of NGC 6357 the Lobster nebula (3) 20 minute subframes 4.5" F/4 astrograph. Processing has been limited to a non linear screen stretch to preserve the delicate structure of the surrounding nebula. Part of the Cat Paw nebula is also visible in the lower right corner. North is up. NGC 6357 spans about 400 light years and lies about 8,000 light years away. This nebula includes the open cluster Pismis 24, which is home to several massive stars.