by 1801 in reference to a catalogue of about 100 nebulae, star clusters and galaxies begun in 1758 by French astronomer and comet-hunter Charles Messier (1730-1817), who was deceived in his telescopic searches by fuzzy objects that resembled distant comets but turned out to be fixed.
What caused me to undertake the catalog was the nebula I discovered above the southern horn of Taurus on September 12, 1758, whilst observing the comet of that year. This nebula had such a resemblance to a comet in its form and brightness that I endeavored to find others, so that astronomers would no more confuse these same nebulae with comets just beginning to appear. [Messier, 1800]
The first version of the catalogue was published 1771, and the fuller version in 1781.
updated on December 31, 2018