Whirlpool Galaxy

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{{Galaxy | name = Whirlpool Galaxy | image = Image:Whirlpool (M51).jpg Whirlpool Galaxy with NGC 5195 (top) | type = SA(s)c: I pec. | epoch = J2000.0 | ra = 13^h 29^m 52.1^s | dec = +47° 11' 43" | dist_ly = 37 million ly | z = +600 | appmag_v = +8.4 | size_v = 11' × 7.8' | constellation name = Canes Venatici | radius_ly = 25,000 ly | absmag_v = 12.7 | notes = satellite galaxy NGC 5195 | names = M51, NGC 5194, Arp 85 }}

The Whirlpool Galaxy (also known as M51 or NGC 5194) is an unbarred spiral galaxy about 37 million light-years distant in the constellation Canes Venatici. It is one of the brightest, most compelling galaxies in the sky, visible through binoculars. It is also a dominant member of the M101 group of galaxies (M51 subgroup).

1 Discovery
2 Other images
3 See also
4 References
5 External links

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Discovery

It was discovered by Charles Messier on October 13, 1773. Its companion galaxy, NGC 5195, was discovered in 1781 by Pierre Méchain. It was however only by 1845 that the Whirlpool Galaxy became the first galaxy to be recognised as a spiral. This was achieved at Birr Castle, Ireland, where the third Earl of Rosse constructed a 72 inch reflector. In 2005 a supernova (SN 2005cs) was observed in the Whirlpool Galaxy, peaking at apparent magnitude 14. [1]. Sometimes M51 is used to refer to the pair of galaxies, in which case the individual galaxies may be referred to as M51A (NGC 5194) and M51B (NGC 5195). Image:M51Sketch.jpg