Supernova remnant W49B, composite image. Located 35 thousand light years away in the Aquila constellation, this image shows an intense X-ray source (blue), surrounded by infrared rings (red and green). The X-ray source is 15 million degree Celsius gas comprised of iron and nickel ions, whereas the infrared sources are mainly hydrogen molecules. It is believed these formations are the aftermath of a massive star which shone for a few million years, spinning off rings of gas. Eventually losing most of its fuel it collapsed to form a black hole, ejecting material rich in iron and nickel. This material hit the cloud surrounding the star, flaring out and creating a shockwave. Chandra and Palomar space telescopes.