When a star comes to the end of its life and dies, it can be an epic and destructive event, throwing out an explosion of heat and light — but it can create stunning new forms as well. A gorgeous new image from the Hubble Space Telescope shows what can be created by the death of a star, featuring a striking object called a planetary nebula.
The name planetary nebula is confusing, as these objects don’t actually have anything to do with planets. They were given that name by early astronomers, who saw round objects through their telescopes and assumed they were distant planets. In fact, they are clouds of dust and gas created by dying stars.
This particular planetary nebula is called Kohoutek 4-55, and is located within the Milky Way around 4,600 light-years away. The different colors of the image represent different elements thrown off by a star as it died.
“Planetary nebulae are the spectacular final display at the end of a giant star’s life,” NASA explains. “Once a red giant star has exhausted its available fuel and shed its last layers of gas, its compact core will contract further, enabling a final burst of nuclear fusion. The exposed core reaches extremely hot temperatures, radiating ultraviolet light that energizes the enormous clouds of gas cast off by the star. The ultraviolet light ionizes atoms in the gas, making the clouds glow brightly. In this image, red and orange indicate nitrogen, green is hydrogen, and blue shows oxygen.”
The particular structure of Kohoutek 4-55 is unusual, as it features several different layers which show up as rings of different colors. This phase will only last a short time, compared to the life of a star, as within a few ten of thousands of years the glowing clouds of gases will have dissipated to leave just the core of a the dead star behind, in the form of a white dwarf.
This image marks a bittersweet moment for Hubble too, as it is the last image that will use data from one of Hubble’s instruments, the Wide Field and Planetary Camera 2. This instrument was replaced by the newer Wide Field Camera 3 in 2009, but scientists have been making use of the data from the older instrument for the last 16 years — including some of the last data it took before replacement, which has been processed using today’s newest techniques to produce this stunning image.
