Changes

}}

}}

The '''Crab Nebula''', also know as '''M1''' and '''NGC 1952''', is an expanding gas cloud surrounding a [[neutron star]] located in the constellation of [[Taurus]] near the star [[Zeta Tauri]], the south horn of the bull. Possibly the most famous [[nebula]], it is the result of a [[supernova]] event that was first observed on [[Earth]] in 1054 A.D.  Since then, the nebula has been expanding at a rate of 1500&nbsp;km/s and is now on average some 11 light years in diameter.<ref>http://apod.nasa.gov/apod/ap011227.html</ref>

The '''Crab Nebula''', also known as '''M1''' and '''NGC 1952''', is an expanding gas cloud surrounding a [[neutron star]] located in the constellation of [[Taurus]] near the star [[Zeta Tauri]], the south horn of the bull. Possibly the most famous [[nebula]], it is the result of a [[supernova]] event that was first observed on [[Earth]] in 1054 A.D.  Since then, the nebula has been expanding at a rate of 1500&nbsp;km/s and is now on average some 11 light years in diameter.<ref>http://apod.nasa.gov/apod/ap011227.html</ref>

==Supernova Event==

==Supernova Event==

The name "Crab Nebula" itself originated from a drawing of the nebula made by '''Lord Rosse''' in 1844, where the supernova remnant looked like a crab.<ref>http://seds.org/MESSIER/more/m001_rosse.html</ref>

The name "Crab Nebula" itself originated from a drawing of the nebula made by '''Lord Rosse''' in 1844, where the supernova remnant looked like a crab.<ref>http://seds.org/MESSIER/more/m001_rosse.html</ref>

In 1892 the first [[photograph]] was taken of the nebula using a 20 inch [[telescope]].  Later in 1921 it was discovered that the nebula was expanding at a rate that allowed for the tracing of its origin to about 900 years before.<ref>http://adsabs.harvard.edu/abs/1921PNAS....7..179D</ref>  In the same year it was independently realized that the nebula was in the proximity of the supernova SN1054.  These two observations led to the revelation that the nebula was the remnant of that same supernova event.<ref>http://adsabs.harvard.edu/abs/1921PASP...33..225L</ref>

In 1892 the first [[photograph]] was taken of the nebula using a 20-inch [[telescope]].  Later in 1921 it was discovered that the nebula was expanding at a rate that allowed for the tracing of its origin to about 900 years before.<ref>http://adsabs.harvard.edu/abs/1921PNAS....7..179D</ref>  In the same year it was independently realized that the nebula was in the proximity of the supernova SN1054.  These two observations led to the revelation that the nebula was the remnant of that same supernova event.<ref>http://adsabs.harvard.edu/abs/1921PASP...33..225L</ref>

Later in 1949, the nebula was discovered to be a strong source of [[radio waves]].<ref>http://adsabs.harvard.edu/abs/1949Natur.164..101B</ref>  In 1963 it was discovered that the nebula was also a major source of [[x-rays|x-ray]], emitting x-ray [[radiation]] at 100 times the energy the nebula emits energy in the visual spectrum.<ref>http://www.sciencemag.org/cgi/content/abstract/146/3646/912</ref> Eventually the source of this energy was discovered in 1968, when a radio [[pulsar]], later revealed to be a neutron star, was found.

Later in 1949, the nebula was discovered to be a strong source of [[radio waves]].<ref>http://adsabs.harvard.edu/abs/1949Natur.164..101B</ref>  In 1963 it was discovered that the nebula was also a major source of [[x-rays|x-ray]], emitting x-ray [[radiation]] at 100 times the energy the nebula emits energy in the visual spectrum.<ref>http://www.sciencemag.org/cgi/content/abstract/146/3646/912</ref> Eventually the source of this energy was discovered in 1968, when a radio [[pulsar]], later revealed to be a neutron star, was found.

===Crab Pulsar===

===Crab Pulsar===

The '''Crab Pulsar''' is a a rapidly rotating [[neutron star]] some 28-30 kilometers in diameter, and has a mass twice that of the [[Sun]].<ref>http://adsabs.harvard.edu/abs/2002A%26A...396..917B</ref>  The pulsar rotates once every 33 milliseconds, emitting radiation towards us once per rotation.  This allows us to measure its rotational speed at 6.4 million km/h.  The pulsar is slowing down though, rotating 15 microseconds slower each year.  The [[radiation]] emitted though from the remnant pulsar is enough to illuminate the entire Crab Nebula with a total luminosity some 75,000 time greater then our Sun.<ref>http://www.solstation.com/x-objects/crab-neb.htm</ref>

The '''Crab Pulsar''' is a rapidly rotating [[neutron star]] some 28-30 kilometers in diameter, and has a mass twice that of the [[Sun]].<ref>http://adsabs.harvard.edu/abs/2002A%26A...396..917B</ref>  The pulsar rotates once every 33 milliseconds, emitting radiation towards us once per rotation.  This allows us to measure its rotational speed at 6.4 million km/h.  The pulsar is slowing down though, rotating 15 microseconds slower each year.  The [[radiation]] emitted though from the remnant pulsar is enough to illuminate the entire Crab Nebula with a total luminosity some 75,000 time greater than our Sun.<ref>http://www.solstation.com/x-objects/crab-neb.htm</ref>

[[Category:Astronomy]]

[[Category:Astronomy]]