Crab Nebula

Crab Nebula
Supernova remnant
Hubble Space Telescope mosaic image assembled from 24 individual Wide Field and Planetary Camera 2 exposures taken in October 1999, January 2000, and December 2000
Observation data: J2000.0 epoch
Right ascension05h 34m 31.94s[1]
Declination+22° 00′ 52.2″[1]
Distance6500±1600 ly   (2000±500[2] pc)
Apparent magnitude (V)8.4[3]
Apparent dimensions (V)420″ × 290″[4][a]
ConstellationTaurus
Physical characteristics
Radius~5.5 ly   (~1.7[5] pc)
Absolute magnitude (V)−3.1±0.5[b]
Notable featuresOptical pulsar
DesignationsMessier 1, NGC 1952, Taurus A, Sh2-244[1]
See also: Lists of nebulae

The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant and pulsar wind nebula in the constellation of Taurus. The common name comes from a drawing that somewhat resembled a crab with arms produced by William Parsons, 3rd Earl of Rosse, in 1842 or 1843 using a 36-inch (91 cm) telescope.[6] The nebula was discovered by English astronomer John Bevis in 1731. It corresponds with a bright supernova recorded by Chinese astronomers in 1054 as a guest star. The nebula was the first astronomical object identified that corresponds with a historically-observed supernova explosion.[7]

At an apparent magnitude of 8.4, comparable to that of Saturn's moon Titan, it is not visible to the naked eye but can be made out using binoculars under favourable conditions. The nebula lies in the Perseus Arm of the Milky Way galaxy, at a distance of about 2.0 kiloparsecs (6,500 ly) from Earth. It has a diameter of 3.4 parsecs (11 ly), corresponding to an apparent diameter of some 7 arcminutes, and is expanding at a rate of about 1,500 kilometres per second (930 mi/s), or 0.5% of the speed of light.

At the center of the nebula lies the Crab Pulsar, a neutron star 28–30 kilometres (17–19 mi) across with a spin rate of 30.2 times per second, which emits pulses of radiation from gamma rays to radio waves. At X-ray and gamma ray energies above 30 keV, the Crab Nebula is generally the brightest persistent gamma-ray source in the sky, with measured flux extending to above 10 TeV. The nebula's radiation allows detailed study of celestial bodies that occult it. In the 1950s and 1960s, the Sun's corona was mapped from observations of the Crab Nebula's radio waves passing through it, and in 2003, the thickness of the atmosphere of Saturn's moon Titan was measured as it blocked out X-rays from the nebula.

  1. ^ a b c "M 1". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 12 February 2012.
  2. ^ Kaplan, David L.; et al. (2008). "A Precise Proper Motion for the Crab Pulsar, and the Difficulty of Testing Spin-Kick Alignment for Young Neutron Stars". The Astrophysical Journal. 677 (2): 1201–1215. arXiv:0801.1142. Bibcode:2008ApJ...677.1201K. doi:10.1086/529026. S2CID 17840947.
  3. ^ "Messier 1". SEDS Messier Catalog. Retrieved 27 April 2022.
  4. ^ Cite error: The named reference Trimble1973 was invoked but never defined (see the help page).
  5. ^ Hester, J. J. (2008). "The Crab Nebula: An Astrophysical Chimera". Annual Review of Astronomy and Astrophysics. 46: 127–155. Bibcode:2008ARA&A..46..127H. doi:10.1146/annurev.astro.45.051806.110608.
  6. ^ Ridpath, Ian. "Lord Rosse and the Crab Nebula". Star Tales. Retrieved 6 September 2023.
  7. ^ Garner, Rob (6 October 2017). "Messier 1 (The Crab Nebula)". NASA. Retrieved 27 April 2022.

From Wikipedia, the free encyclopedia · View on Wikipedia

Developed by Nelliwinne