Planetary nebula M57 (NGC 6720) in Lyra - The Ring nebula M57 in Lyra -...

Planetary nebula M57 (NGC 6720) in Lyra - The Ring nebula M57 in Lyra - The planetary nebula of Lyra (M57) is located about 2000 years - light from Earth. A planetary nebula is a gas shell from a small late-life star whose heart collapsed to become a white dwarf and expelled the outer layers of its matter. Image obtained by the Hubble Space Telescope and the Large Binocular Telescope. In this composite image, visible - light observations by Nasa's Hubble Space Telescope are combined with infrared data from the ground - based Large Binocular Telescope in Arizona to assemble a dramatic view of the well - known Ring Nebula. Called a planetary nebula, the Ring Nebula is the glowing remains of a Sun - like star. The object is tilted towards Earth so that astronomers see the ring face - on. The Hubble observations reveal that the nebula's shape is more complicated than astronomers thought. The blue gas in the nebula's center is actually a football - shaped structure that pierces the red doughnut - shaped material. Hubble also uncovers the detailed structure of the dark, irregular knots of dense gas embedded along the inner rim of the ring. The knots look like spokes in a bicycle. The Hubble images have allowed the research team to match up the knots with the spikes of light around the bright, main ring, which are a shadow effect. The faint, scallop - shaped material surrounding the ring was expelled by the star during the early stages of the planetary nebula formation. This outer material was imaged by the Large Binocular Telescope. Most Sun - like stars become planetary nebulae at the end of their lives. Once a star consumes all of its hydrogen, the nuclear fuel that makes it shine, it expands to a red giant. The bloated star then expels its outer layers, exposing its hot core. Ultraviolet radiation from the core illuminates the discarded material, making it glow. The smoldering core, called a whi