M108

Messier 108 (M108) is a spiral galaxy in the northern constellation Ursa Major. It is one of the fainter Messier objects, presenting an elongated appearance when viewed through a telescope. Distance estimates place it at roughly 35 to 40 million light-years (about 11 to 12 megaparsecs) from Earth. The galaxy is also catalogued as NGC 3556.

Discovery and observations: M108 was discovered by Pierre Méchain in 1781 and subsequently included in Charles Messier’s catalog. In both amateur and professional astronomy, it is typically studied under dark-sky conditions with long-exposure imaging due to its relatively low surface brightness.

Morphology and structure: The galaxy is observed nearly edge-on, revealing a prominent central bulge and a dust lane across the disk. Its spiral structure is not strongly defined, and it is often described as an intermediate-type spiral galaxy, with a modest rate of star formation in the inner regions and a relatively quiescent outer disk.

Observational context: M108 lies in the general Ursa Major region alongside other Messier objects, and it has been included in surveys of the local galaxy population. Studies focus on disk kinematics, dust content, and the properties of its inner star-forming regions, contributing to a broader understanding of spiral galaxy evolution.