Pierre Méchain

Pierre François André Mechain (1744-1804) was a French astronomer and surveyor best known for his work alongside Charles Messier cataloguing comets and deep-sky objects, and for later contributing his own new entries to the Messier Catalogue of nebulae and star clusters. Working from Paris in the 1780s, Mechain discovered numerous comets and nebulae, several of which he and Messier confirmed together were not comets but fixed, extended objects worth recording so future observers would not mistake them for the same. Mechain also worked as a surveyor, and in the 1790s he and fellow astronomer Jean-Baptiste Delambre undertook a multi-year geodetic survey between Dunkirk and Barcelona to measure the meridian arc, work commissioned to establish the length of the meter as one ten-millionth of the distance from the pole to the equator. Mechain died of yellow fever in Spain in 1804 while attempting to extend the survey further south.