How to Spot New Supernova in Nearby Galaxy | Exploded Stars & Supernovas | PTF 11 kly & SN2011fe | Space.com: "Frenchman Pierre Mechain was the first to see this galaxy in 1781. Later that same year, it was observed by Charles Messier, who described it as appearing as "A nebula without star, very obscure and pretty large."
Messier would later include this galaxy as the 101st object in the final (1781) version of his famous catalog of comet masqueraders, hence "M" (for Messier) 101. It was one of the first "spiral nebulas" identified as such, in 1851 by William Parsons, the third Earl of Rosse.
Today, M101 sometimes goes by the popular moniker "The Pinwheel Galaxy." The name is quite appropriate, as observatory photographs show it as an impressive system with well-defined spiral arms. [Stunning Galaxy Photos from NASA's WISE Telescope]"
'via Blog this'