Well would you look at that, it’s APOD time again.
In 185 AD, Chinese astronomers recorded the appearance of a new star in the Nanmen asterism – a part of the sky identified with Alpha and Beta Centauri on modern star charts. The new star was visible for months and is thought to be the earliest recorded supernova. This multiwavelength composite image from orbiting telescopes of the 21st century, XMM-Newton and Chandra in X-rays, and Spitzer and WISE in infrared, shows RCW 86, understood to be the remnant of that stellar explosion. The false-color view traces interstellar gas heated by the expanding supernova shock wave at X-ray energies (blue and green) and interstellar dust radiating at cooler temperatures in infrared light (yellow and red).