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Messier 1 NGC 1952 The Crab Nebula
Imaged by Martin S. Ferlito copyright
Gstar-EX Integrating Video Camera
8" Schmidt-Cassegrain on Vixen GP Mount, Stepper Driven. 
Information provided by seds.org


Discovered 1731 by British amateur astronomer John Bevis.
The Crab Nebula, Messier 1 (M1, NGC 1952), is the most famous and conspicuous known supernova remnant, the expanding cloud of gas created in the explosion of a star as supernova which was observed in the year 1054 AD. It shines as a nebula of magnitude 8.4 near the southern "horn" of Taurus, the Bull.
The supernova was noted on July 4, 1054 A.D. by Chinese astronomers as a new or "guest star," and was about four times brighter than Venus, or about mag -6. According to the records, it was visible in daylight for 23 days, and 653 days to the naked eye in the night sky. It was probably also recorded by Anasazi Indian artists (in present-day Arizona and New Mexico), as findings in Navaho Canyon and White Mesa (both Arizona) as well as in the Chaco Canyon National Park (New Mexico) indicate; there's a review of the research on the Chaco Canyon Anasazi art online. In addition, Ralph R. Robbins of the University of Texas has found Mimbres Indian art from New Mexico, possibly depicting the supernova.
The Supernova 1054 was also assigned the variable star designation CM Tauri. It is one of few historically observed supernovae in our Milky Way Galaxy.The nebulous remnant was discovered by John Bevis in 1731, who added it to his sky atlas, Uranographia Britannica. Charles Messier independently found it on August 28, 1758, when he was looking for comet Halley on its first predicted return, and first thought it was a comet. Of course, he soon recognized that it had no apparent proper motion, and cataloged it on September 12, 1758. It was the discovery of this object which caused Charles Messier to begin with the compilation of his catalog. It was also the discovery of this object, which closely resembled a comet (1758 De la Nux, C/1758 K1) in his small refracting telescope, which brought him to the idea to search for comets with telescopes (see his note). Messier acknowledged the prior, original discovery by Bevis when he learned of it in a letter of June 10, 1771.
Although Messier's catalog was primarily compiled for preventing confusion of these objects with comets, M1 was again confused with comet Halley on the occasion of that comet's second predicted return in 1835.
The nebula consists of the material ejected in the supernova explosion, which has been spread over a volume approximately 10 light years in diameter, and is still expanding at the very high velocity of about 1,800 km/sec. The notion of gaseous filaments and a continuum background was photographically confirmed by Walter Baade and Rudolph Minkowski in 1930: The filaments are apparently the remnants from the former outer layers of the former star (the "pre-supernova" or supernova "progenitor"), while the inner, blueish nebula emits continuous light consisting of highly polarised so-called synchrotron radiation, which is emitted by high-energy (fast moving) electrons in a strong magnetic field. This explanation was first proposed by the Soviet astronomer J. Shklovsky (1953) and supported by observations of Jan H. Oort and T. Walraven (1956). 



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