On July 4, 1054, Chinese astronomers noted a “guest star” in the Taurus stars. Later studies revealed coexistent observations in Japan and the Middle East.
Momentarily surpassing Venus, it disappeared after almost two years, a typical supernova. Hundreds of years later, its remains were astronomically discovered. John Bevis discovered it in 1731, but it was a big source of uncertainty in 1758.
Halley’s comet was due to return that year, too in Taurus. But, this vague, fuzzy, dim sight perplexed many. It wasn’t a comet, but a faraway object ~6,500 light-years away.
Rediscovered independently by Charles Messier, it sparked the formation of astronomy’s most popular catalogue. Almost a millennium later, we actively find this remnant growing.
Its central engine is equipped by a pulsing neutron star, the fallen core of a very large star. In the meantime, the previous star’s outer layers were removed at extreme speeds.
Smashing into earlier ejecta and illuminated by radiation, they’re brightly evident today. After 967 years, almost a complete millennium, this supernova remnant traverses across 11 light-years.
Its outskirts are still growing at ~0.5% of the speed of light. The elements spotted inside symbolise that these type II supernovae produce the majority of many heavy elements.