Swan Lace - detail - This delicate Hubble Space Telescope image shows a tiny portion...

Swan Lace - detail - This delicate Hubble Space Telescope image shows a tiny portion of the Cygnus loop, a supernova remnant in the constellation of Cygnus, the Swan. Measurements on this super - detailed image of a cosmic veil shows that the original supernova explosion took place only 5000 years ago. The Cygnus loop, also known as the Veil Nebula, is well - known to amateur astronomers as a challenging target for larger telescopes. It has a diameter of about 3 degrees (corresponding to 6 full moons). This spectacular nebula was created when a massive star ended its days in an immense supernova explosion. A bubble of dust and gas was expelled into space and has continued to expand outwards ever since. The Cygnus Loop consists of two main arcs, designated NGC 6992/95 for the Eastern arc and NGC 6960 for the Western arc (also called the Witch's Broom Nebula). The tiny area of the Hubble image is seen in the upper left - hand corner of the nebula, at the outer edge of one of the large filaments, just where the blast wave rams into the surrounding interstellar gas. We are seeing the shock front almost exactly edge - on, thus explaining its wispy, sheet - like appearance. The image is a striking example of how processes that take place hundreds of light years away can sometimes resemble effects we see around us in our daily life. It was obtained with the WFPC2 instrument in November 1997 with an exposure time of 7400 seconds. The image shows light emitted by neutral hydrogen (656.3 nm) and measures 150 x 70 arc - seconds