Editing Crab Nebula (section)

===First identification===
[[File:M1rosse.jpg|thumb|left|upright|Reproduction of the first depiction of the nebula by [[Lord Rosse]] (1844) (colour-inverted to appear white-on-black)]]
[[File:The Crab Nebula M1 Goran Nilsson & The Liverpool Telescope.jpg|thumb|[[H-alpha|HaRGB]] image of the Crab Nebula from the [[Liverpool Telescope]], exposures totalling 1.4 hours.]]
[[File:Stack 252frames 8064s ps-.jpg|thumb|The Crab Nebula M1]]
The Crab Nebula was first identified in 1731 by [[John Bevis]].<ref name=Barrow2008>{{cite book |last1=Barrow |first1=John D. |title=Cosmic Imagery: Key Images in the History of Science |publisher=Random House |page=45 |date=2008 |url=https://books.google.com/books?id=uRg6iN10JCIC&pg=PA45 |isbn=978-0-224-07523-7}}</ref> The nebula was independently rediscovered in 1758 by [[Charles Messier]] as he was observing a bright [[comet]].<ref name=Barrow2008/> Messier catalogued it as the first entry in his [[Messier Catalogue|catalogue]] of comet-like objects;<ref name=Barrow2008/> in 1757, [[Alexis Clairaut]] reexamined the calculations of [[Edmund Halley]] and predicted the return of [[Halley's Comet]] in late 1758. The exact time of the comet's return required the consideration of perturbations to its orbit caused by planets in the Solar System such as Jupiter, which Clairaut and his two colleagues [[Jérôme Lalande]] and [[Nicole-Reine Lepaute]] carried out more precisely than Halley, finding that the comet should appear in the [[constellation]] of [[Taurus (constellation)|Taurus]]. It was in searching in vain for the comet that [[Charles Messier]] found the Crab Nebula, which he at first thought to be Halley's comet.<ref name=Pugh2011>{{cite book |last1=Pugh |first1=Philip |title=Observing the Messier Objects with a Small Telescope: In the Footsteps of a Great Observer |publisher=Springer Science |pages=8–10 |date=November 2011 |url=https://books.google.com/books?id=jDbjx-FSv5cC&pg=PA10 |isbn=978-0-387-85357-4}}</ref> After some observation, noticing that the object that he was observing was not moving across the sky, Messier concluded that the object was not a comet. Messier then realised the usefulness of compiling a catalogue of celestial objects of a cloudy nature, but fixed in the sky, to avoid incorrectly cataloguing them as comets. This realization led him to compile the "[[Messier object|Messier catalogue]]".<ref name=Pugh2011/>

[[William Herschel]] observed the Crab Nebula numerous times between 1783 and 1809, but it is not known whether he was aware of its existence in 1783, or if he discovered it independently of Messier and Bevis. After several observations, he concluded that it was composed of a group of stars.<ref name="Mayall"/> [[William Parsons, 3rd Earl of Rosse]] observed the nebula at [[Birr Castle]] in the early 1840s using a {{convert|36|in|m|1|adj=on}} telescope, and made a drawing of it that showed it with arms like those of a crab.<ref name=Ridpath/> He observed it again later, in 1848, using a {{convert|72|in|m|1|adj=on}} telescope but could not confirm the supposed resemblance, but the name stuck nevertheless.<ref>{{cite journal |last=Parsons |first=William |title=Observations on Some of the Nebulae |journal=Philosophical Transactions of the Royal Society of London |volume=134 |date=1844 |at=fig. 81, plate xviii, p. 321 |url=https://archive.org/stream/jstor-108366/108366#page/n5/mode/2up |jstor=108366 |doi=10.1098/rstl.1844.0012|s2cid=186212669 }}</ref><ref>{{cite book |last=Jones |first=Kenneth Glyn |title=The Search for the Nebulae |publisher=Alpha Academic |date=1975 |isbn=978-0-905193-01-4 |url=https://books.google.com/books?id=vGW1AAAAIAAJ}}</ref>