The Andromeda Galaxy (M31) is a large spiral galaxy located about 2.5 million light-years from Earth in the constellation Andromeda. It is the nearest major galaxy to the Milky Way and the largest in the Local Group, which includes the Milky Way and the Triangulum Galaxy. With a diameter of roughly 220,000 light-years, Andromeda contains about a trillion stars. It is moving toward the Milky Way and is expected to merge with our galaxy in about 4.5 billion years. Andromeda is visible to the naked eye from dark-sky locations and is a popular target for astronomers.

The M33 (Messier 33), also known as the Triangulum Galaxy, is a spiral galaxy located in the constellation Triangulum. It is the third-largest member of the Local Group of galaxies, after the Andromeda Galaxy (M31) and the Milky Way. M33 is approximately 2.73 million light-years away and has a diameter of about 60,000 light-years, making it smaller than the Milky Way. Known for its bright H II regions, such as NGC 604, it is an active star-forming galaxy. M33 is a popular target for astrophotographers and astronomers due to its proximity and rich structure.