Messier 106 (M106 / NGC 4258) was discovered by Pierre Méchain in 1781 and later added to the Messier catalog. It is a bright barred spiral galaxy located about 21–25 million light-years away, moving away from us at roughly 537 km/s. Its classification varies between Sb and SABbc, reflecting its intermediate structure between normal and barred spirals. Because of its inclination, M106 shows prominent dust lanes and spiral structure similar to Andromeda Galaxy. Its spiral arms contain bright blue star-forming regions—young clusters of massive, short-lived stars—while older, yellowish regions trace earlier generations of stars, hundreds of millions of years old. M106 is also an active galaxy with a Seyfert 1.9 nucleus. At its center lies a supermassive black hole of about 36 million solar masses, surrounded by a dense disk producing powerful microwave maser emission. This maser has enabled one of the most precise geometric distance measurements to a galaxy. Additionally, M106 emits radio jets from its core and has hosted observed supernovae, including SN 1981K and SN 2014bc.