Messier 33, also known as the Triangulum Galaxy, is a spiral galaxy located approximately 3 million light-years from Earth. It is the third-largest member of the Local Group, which includes the Milky Way and the Andromeda Galaxy. Messier 33 has a diameter of about 60,000 light-years and contains several regions of active star formation. This galaxy is notable for its bright, prominent spiral arms and a relatively low surface brightness. It is best observed with small telescopes and is often studied for its numerous H II regions, which are areas of ionized hydrogen gas where new stars are being born.