PIX4623552: Planetary nebula NGC 7027 in the Swan/HST - This NASA Hubble Space Telescope image of planetary nebula NGC 7027 shows remarkable new details of the process by which a star like the Sun dies. New features include: faint, blue, concentric shells surrounding the nebula; an extensive network of red dust clouds throughout the bright inner region; and the hot central white dwarf, visible as a white dot at the center. The nebula is a record of the star's final death throes. Initially the ejection of the star's outer layers, when it was at its red giant stage of evolution, occurred at a low rate and was spherical. The Hubble photo reveals that the initial ejections occurred episodically to produce the concentric shells. This culminated in a vigorous ejection of all of the remaining outer layers, which produced the bright inner regions. At this later stage the ejection was non - spherical, and dense clouds of dust condensed from the ejected material. NGC 7027 is located about 3,000 light - years from Earth in the direction of the summer constellation Cygnus. When a star like the Sun nears the end of its life, it expands to more than 50 times its original diameter, becoming a red giant star. Then its outer layers are ejected into space, exposing the small, extremely hot core of the star, which cools off to become a white dwarf. Although stars like the Sun can live for up to 10 billion years before becoming a red giant and ejecting a nebula, the actual ejection process takes only a few thousand years. The NGC 7027 photograph is a composite of two Hubble images, taken in visible and infrared light, and is shown in “” pseudo - color. / Bridgeman Images
PIX4623677: Planetary nebula IC 418 dans le Lievre/HST - IC 418: The “” Spirograph” Nebula Glowing like a multi - faceted jewel, the planetary nebula IC 418 lies about 2,000 light - years from Earth in the direction of the constellation Lepus. This photograph is from Nasa's Hubble Space Telescope, obtained with the Wide Field Planetary Camera 2. A planetary nebula represents the final stage in the evolution of a star similar to our Sun. The star at the center of IC 418 was a red giant a few thousand years ago, but then ejected its outer layers into space to form the nebula, which has now expanded to a diameter of about 0.1 light - year. The stellar remnant at the center is the hot core of the red giant, from which ultraviolet radiation floods out into the surrounding gas, causing it to fluoresce. Over the next several thousand years, the nebula will gradually disperse into space, and then the star will cool and fade away for billions of years as a white dwarf. Our own Sun is expected to undergo a similar fate, but fortunately this will not occur until some 5 billion years from now. The Hubble image of IC 418 is shown in a false - color representation, based on Wide Field Planetary Camera 2 exposures taken in February and September, 1999 through filters that isolate light from various chemical elements. Red shows emission from ionized nitrogen (the coolest gas in the nebula, located furthest from the hot nucleus), green shows emission from hydrogen, and blue traces the emission from ionized oxygen (the hottest gas, closest to the central star) / Bridgeman Images