The Crab Nebula is located in Taurus, about 6,500 light years away from the Earth, with a size of about 12×7 light years and a brightness of 8.5 magnitude, which is invisible to the naked eye. The earliest record of the Crab Nebula came from an astronomer in China. In July 1054, an official named Yang in China reported to the emperor that a "guest star" appeared in the sky. British astronomy enthusiast (173 1), French astronomer messier left the position of 1 to the Crab Nebula when he made the famous Catalogue of Nebulae and Clusters (M) in 1. 1892, American astronomers took the first picture of the crab nebula. Thirty years later, when astronomers compared the previous photos of the Crab Nebula, they found that it was expanding at the speed of 1 100 km/s, so people became interested in the origin of the Crab Nebula. Because the expansion speed of the crab nebula is very fast, astronomers calculate its formation time according to this speed, and come to the conclusion that the crab nebula was probably only the size of a star more than 900 years ago. Therefore, in 1928, Hubble, an American astronomer, first associated it with supernovae and thought that the Crab Nebula was a relic left after the supernova explosion in 1054.
Supernova vestige type
Right ascension 05h 34m 3 1.97s
Declination+22 00' 52.1"
6300 light years away
Apparent magnitude +8.4
Apparent diameter 6×4 angular minutes
Taurus constellation
A radius of 3 light years
Absolute magnitude -3
1054
Astronomers in ancient China first discovered the celestial guest star. 173 1 year, British doctor and astronomy enthusiast Bevis discovered the crab nebula. 1758, messier ranked the crab nebula in his nebula listNo. 1, which was called M 1.
1850
Ross was named "Crab Nebula". In 19 10, Lambland first noticed the "cluster" structure. 192 1 year, Lambrand and Duncan independently discovered that the crab nebula was expanding. 1928, Hubble measured the expansion speed of the Crab Nebula, and concluded that it was the remains of the Celestial Star discovered in China.
1948
Radio observation shows that it is a strong radio source. 1953, Shkolovsky proposed that the radio emission mechanism of the crab nebula is synchrotron radiation, which was quickly confirmed by optical polarization observation.
1957
Radio polarization observation is successful. The Crab Nebula was discovered as an X-ray source in 1963. A dense source was found near the center of 1964.
1968
It is found that the Crab Nebula is a gamma ray source. The crab nebula pulsar NP0532 (unified name PSR 053 1+2 1) was discovered in 1968. 1969 discovered that NP0532 is also an optical pulsar.