Monday, 4 July 2022

♉︎ ⍺

First observed by sky-watchers in China on this day in 1054 (such temporary spectres were called generically “guest stars” 客星) and visible, easily to amateur astronomers to this day as the stellar remnant known as the Crab Nebula Supernova (SN) 1054 is perhaps one of the best known examples, though it’s nature and origin were unknown until very recently. Anticipating the return of Halley’s Comet in 1758 (see also), Charles Messier confused the static plerion for the returning traveller and was motivated by his mistake to create a catalogue of the celestial sphere, with the Crab Nebula labeled as the first Messier object, M1.