The Messier Catalogue is a list of astronomical objects compiled by the French astronomer Charles Messier in the 18th century. It includes 110 objects, such as star clusters, nebulae, and galaxies, which are primarily located in the northern hemisphere. Messier created this catalogue to help astronomers distinguish between these permanent objects and transient comets. Each object in the Messier Catalogue is designated with an "M" followed by a number, like M31 for the Andromeda Galaxy. The catalogue is widely used by amateur and professional astronomers for observing deep-sky objects, serving as a valuable reference in the study of the universe.