The Crab Nebula (M1)
The Crab Nebula is the first astronomical object identified as the remnant of a supernova that was recorded by human observers in history. It corresponds to a bright “guest star” seen in AD 1054 and noted by Mayan, Japanese, and Arab stargazers, and by Chinese astronomers.
Briefing
The Crab Nebula (M1, NGC 1952, Taurus A) is a supernova remnant and pulsar wind nebula in the constellation Taurus. It lies in the Perseus Arm of the Milky Way at a distance of about 2.0 kiloparsecs (6,500 light-years) from Earth, spans 3.4 parsecs (11 light-years) in diameter, and appears about 7 arcminutes across on the sky; it is expanding at about 1,500 kilometres per second (930 mi/s), or 0.5% of the speed of light.
How we know
Knowledge of the Crab Nebula is anchored in two kinds of records that meet across a millennium: written skywatching and telescopic observation. Chinese astronomers described the AD 1054 supernova as a “guest star,” and accounts also exist from Mayan, Japanese, and Arab stargazers; the nebula is identified as the surviving remnant of that historically observed explosion. In modern astronomy, the object itself entered the telescopic era when John Bevis discovered the nebula in 1731, and its enduring name comes from William Parsons, 3rd Earl of Rosse, who produced a drawing in 1842 or 1843—made with a 36-inch (91 cm) telescope—whose form suggested a crab with outstretched arms.
- Field conditions
- In Taurus, the Crab Nebula is not visible to the naked eye (apparent magnitude 8.4), but can be made out with binoculars under favourable conditions.
