Credit: NASA/JPL-Caltech/B. Williams (NCSU)
The outline of a face show the remains of the oldest documented supernova in this infrared image of RCW 86 from NASA’s Spitzer Space Telescope and Wide-field Infrared Survey Explorer, or WISE.
Explore the dusty glowing remains of this exploded star. What patterns or stories do you see? Leave a note below.
In 185 A.D., the Chinese wrote about a mysterious “guest star” that appeared in the sky. The star remained visible for eight months. The Chinese had no way of knowing they witnessed one of the most powerful events in the universe. Using images from Spitzer and the Wide-field Infrared Survey Explorer, astronomers are able to piece together the story Chinese historians first witnessed nearly 2,000 years ago. RCW 86 is a special kind of supernova. A white dwarf, the dead remains of a star like our Sun, pulled material from a companion star. As this material piles up, it becomes super-hot. Reactions inside the star go haywire and the star explodes. Astronomers call this a Type 1A supernova. Supernova give off so much light energy, they briefly outshine an entire galaxy.
Using the data from the orbiting observatories, astronomers solved another puzzle; how the remnant got so large in just 1,800 years. They found that the white dwarf, with its strong solar wind, created a bubble within the region around the star. The cavity was already huge when the star exploded. When it blew up, a shockwave pushed the edge of the bubble out much quicker than it normally would.
The colors of the image are not real but they do provide scientists important information. Infrared data from Spitzer and WISE are shown in yellow and red. These colors show warm dust in deep space. Blues and greens in the image are from X-ray data taken from NASA’s Chandra X-ray Observatory and the European Space Agency’s XMM-Newton Observatory. The X-rays show gas in deep space that has been heated to millions of degrees as the expanding edge of the supernova passed.
Light from RCW 86 took about 8,200 years to reach the eyes of the Chinese historians. The remains of the “guest star” are found in the faint southern constellation Circinus, the Compass. From Earth, the bubble is slightly larger than a full moon. At this distance, that makes the bubble about 85 light-years across.