"800-Year-Old Supernova Remnants Reveal 'Zombie' Star and Medieval Cosmic Firework"

Astronomers have imaged the remnants of an 800-year-old supernova, known as SNR 1181, located in the constellation Cassiopeia. The composite image from NASA's Chandra X-ray Observatory shows a spherical nebula surrounding a hot white dwarf star, likely formed during the supernova. This "zombie" star, one of the hottest in the Milky Way, resulted from the incomplete explosion of two merging white dwarf stars. Despite being observed 800 years ago, the supernova actually occurred around 10,900 years ago due to its distance from Earth.