French astronomer Charles Messier was a comet hunter who identified over 100 objects that resembled comets but were not. He created a catalogue of these objects so he could avoid them as he continued his search for comets. In 1771 he published the first edition of his catalogue with 45 objects. In subsequent editions the list grew to its current 110 objects. Various types of deep sky objects including diffuse nebulae, planetary nebulae, open clusters, globular clusters and galaxies are represented in the list. Because of this, and the fact that the objects tend to be relatively accessible with simple to moderately powerful amateur equipment, amateur astronomers have enjoyed observing and recording these objects somewhat like a cosmic scavenger hunt. Cataloging all 110 of the objects is quite an achievement. M106 can be found in Canes Venatici just under the tail of the adjacent Ursa Major.
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The Messier Catalog online at seds.org: