The first item in the Messier catalogue is the famous Crab Nebula, a remnant of a supernova explosion observed and recorded by Chinese and Arab astronomers in 1054. The supernova itself was brilliant and with a peak magnitude of –7 was easily visible in daylight. Today, it still rates as one of the brightest natural stellar events ever recorded. Roll on 950+ years and the initial explosive has long since faded but the aftermath - the nebula - remains visible. At mag. +8.4 and with an apparent size of 7x5 arc minutes, it's a relatively easy target under dark skies and can be spotted with a pair of binoculars.
M1 is located in the zodiacal constellation of Taurus. It's not difficult to find as it's positioned just a degree northwest of mag. +3.0 star Zeta Tauri (ζ Tau). The remnant was first observed by John Bevis in 1731. Charles Messier observed it in September 1758 and the appearance of this dying remnant inspired him to begin compiling a list of nebulae that possibly could be mistaken for comets. The list eventually became his famous catalogue. The following century, William Parsons, the Third Earl of Rosse made a drawing of M1 (around 1844) and christened it the Crab Nebula due to its wispy filamentary structure.
M1 is best seen from the Northern Hemisphere during the months of November, December and January.
When viewed through 10x50 binoculars, M1 appears as a reasonably sized oblong patch of light that's more pronounced using averted vision. Larger 20x80mm binoculars or small 80mm (3.1-inch) telescopes show some variations in brightness around the edges, especially on nights of good seeing. A 150mm (6-inch) or 200mm (8-inch) telescope displays the Crab Nebula as a large oval diffuse patch of light with fine streaks visible. A 300mm (12-inch) or larger scope shows more intricate details including twists, filaments and surface variations over the complete face. It's a tantalizing view, that hints at Lord Rosse's famous drawings.
M1 is located about 6,500 light-years from Earth and is the only supernova remnant in Messier's catalogue. It has a radius of 5.5 light-years. At the centre of the nebula is a pulsar, which is the remains of the original star. It's believed to be about 30 km in diameter and emits pulses of radiation every 33 milliseconds.
M1 Data Table
|Object Type||Supernova Remnant|
|RA (J2000)||05h 34m 32s|
|DEC (J2000)||+22d 00m 52s|
|Apparent Size (arc mins)||7.0 x 4.8|
|Other Designation||Sharpless 244|