NASA. This Deep Space image shows a remarkable, near-perfect - Lot 257

NASA. This Deep Space image shows a remarkable, near-perfect ring about 150 light-years across, surrounding a cloud of oxygen-rich gas shock-heated to millions of degrees Celsius. The ring marks the outer limits of a shock wave produced when matter ejected during the supernova explosion plunges into the interstellar gas. The size of the ring indicates that we are looking at the supernova remnant as it was some 10,000 years after the explosion of its parent star. Oxygen is synthesized by nuclear reactions in stars at least ten times more massive than the Sun. When such a star explodes, its core collapses to form a neutron star or, if massive enough, a black hole, and the oxygen-rich matter surrounding the core is propelled into interstellar space. 2003. Vintage chromogenic print. Numbering in the margin on the front. Legend on back label. 25.5 x 20.5CM with margins.