The Crab Nebula
The Crab Nebula (list names M1, NGC 1952, Taurus A) is a pulsar wind nebula in the constellation Taurus, and the remnant of the celestial supernova SN 1054. observed by John Bevis in 1731; it corresponds to the bright supernova recorded by Chinese and Arab astronomers in 1054.
With a spectral peak in the X-ray and gamma-ray regions above 30 KeV, and extending to over 1012 eV, the Crab Nebula is generally the most intensely sustained light source in the sky. Located about 6,500 light-years (2 kpc) from Earth, this nebula is 11 ly (3.4 pc) in diameter and is expanding at a rate of about 1,500 kilometers per second. At the center of this nebula is the pulsar Crab, a rotating neutron star that emits pulses of radiation with wavelengths from gamma rays to radio waves and at a rotational rate of about 30.2 times per second. This nebula is the first object identified by a historic supernova explosion. This nebula serves as a source of radiation to study the objects that obscure it. During the 1950s and 1960s, the Sun's corona was mirrored by radio observations of the Crab Nebula passing it, and in 2003 the thickness of Saturn's atmosphere was Titan. was measured when it intercepted X-rays from this nebula.
The Crab Nebula formation corresponding to the bright supernova SN 1054 was recorded by Chinese and Arab astronomers in 1054. The Crab Nebula was first observed by John Bevis in 1731 and it was first observed by Charles Messier observed again independently in 1758 when he was observing a bright comet. Messier placed it in the first category (M1) of his catalog of comet-like objects. William Parsons observed the nebula at Birr Castle in the 1840s, and named it the Crab Nebula because his drawing of the nebula resembled a crab.
In the early 20th century, analysis of early photographs of the nebula over several years revealed that the nebula was expanding. Tracking past expansion shows that the nebula must have been visible on Earth about 900 years ago. The historical record that a new star bright enough to be seen during the day was recorded by Chinese and Arab astronomers in the same part of the sky in 1054. Given the distance to the massive star, the "guest star" observed by the Chinese and Arabs could only be a supernova; A massive star that has exhausted its fusion energy supply explodes and collapses into itself. Recent analysis of historical data has shown that supernova SN 1054 has been observed. created the Crab Nebula which probably appeared in April or early May, its peak brightness increasing from apparent magnitudes −7 and −4.5 (brighter than other celestial bodies in the outer sky). minus the Moon) in July. The supernova has been observed with the naked eye for about two years. Thanks to the historical records of observations by astronomers of the Far East and the Middle East in 1054, the Crab Nebula became the first astronomical object recorded to be associated with a supernova explosion. In fact, due to the distance t