M33

The Triangulum Galaxy (also known as Messier 33 or NGC 598) is a spiral galaxy approximately 3 million light-years away in the constellation Triangulum. The galaxy is also sometimes informally referred to as the Pinwheel Galaxy by some amateur astronomy references and in some public outreach websites. However, the SIMBAD Astronomical Database, a professional astronomy database that contains formal designations for astronomical objects, indicates that the name "Pinwheel Galaxy" is used to refer to Messier 101, and several other amateur astronomy resources and other public outreach websites also identify Messier 101 by that name. With a diameter of about 50,000 light-years, it is the third largest galaxy in the Local Group, a group of galaxies which also contains the Milky Way Galaxy and the Andromeda Galaxy, and it may be a gravitationally bound companion of the Andromeda Galaxy. Estimates indicate that Triangulum may be home to between 30 and 40 billion stars, compared to the 1000 billion stars for Andromeda and c. 200-400 billion for the Milky Way. The Pisces Dwarf (LGS 3), one of the small Local Group member galaxies, is possibly a satellite of Triangulum. (Wikipedia)