Object Analysis

The Triangulum Galaxy (Messier 33) is a spiral galaxy approximately 3 million light-years from Earth in the constellation Triangulum. It is the third-largest member of the Local Group of galaxies, behind the Andromeda Galaxy and the Milky Way. It is one of the most distant permanent objects that can be viewed with the naked eye under exceptionally dark viewing conditions.

Unlike Andromeda and the Milky Way, Triangulum is an example of a flocculent spiral galaxy, meaning it lacks a clearly defined central bulge and distinct spiral arms, instead exhibiting a "fluffy" appearance. It is actively forming stars at a rate much higher than the Andromeda Galaxy, with vast H II regions scattered throughout its spiral arms.

Triangulum is sometimes called the "Pinwheel Galaxy," though that name is more formally applied to M101. It is gravitationally bound to the Andromeda Galaxy and may actually be orbiting it. This interaction has likely triggered some of the intense star formation seen in Triangulum's large nebulae, such as NGC 604, which is one of the largest star-forming regions in the Local Group.