Follow the Moon as it wanes through the midnight sky this week, and you’ll arrive at the site of a significant celestial event that has occupied and astonished astronomers for centuries.
The event was a supernova that surged into view in 1054, and was recorded by Chinese astronomers at the time, as well as by sky gazers indigenous to the Chaco canyon region of southwest North America.
The supernova is now called the “Crab Nebula”, and it’s near the tip of the Bull’s southern horn, near the Zeta star in Taurus. That star now has the official name Tianguan, and the Moon will be a waning crescent near this star on Sunday morning, so you can look for it about an hour before sunrise, in the east. The star is visible to the naked eye, but the nebula requires binoculars at least.
The Crab Nebula was the first object to be listed in Charles Messier’s famous 18th century catalog. He had been looking for Halley’s Comet in the region of Zeta Tauri in 1758 when he noticed that the thing he thought was it was not actually moving across the sky. He concluded that it was not a comet and he realised that it would be useful to compile a catalogue of such objects, to avoid incorrectly cataloguing them as comets. Messier eventually catalogued 110 nebula and star clusters, objects that are popular to this day as telescopic targets, with amateur and professional astronomers alike.
The Crab Nebula is also known as Messier object #1, or M1, and the Zeta Tauri star near here was regarded in Chinese astronomy as the celestial gate, and in ancient astrological tradition, it was known to have a mischievous influence.
Follow the waning Moon to this region of sky, where it will arrive on Sunday morning, a waning crescent inspiring us all to take the Bull by the horns before that last New Moon of the Summer occurs next week.