Mystery of oldest recorded supernova solved. In 185 A.D., Chinese astronomers noted a “guest star” that mysteriously appeared in the sky and stayed for about eight months. By the 1960s, scientists had determined that the mysterious object was the first documented supernova. Later, they pinpointed the object, known as RCW 86, as a supernova remnant located about 8,000 light-years away but remained puzzled at how the star’s spherical remains were larger than expected.

(Source: nationalpost)