Object: The Triangulum Galaxy is a spiral galaxy 2.73 million light-years from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC 598. The Triangulum Galaxy is the third-largest member of the Local Group of galaxies, behind the Milky Way and the Andromeda Galaxy. It is one of the most distant permanent objects that can be viewed with the naked eye.

The galaxy is the smallest spiral galaxy in the Local Group and it is believed to be a satellite of the Andromeda Galaxy due to their interactions, velocities, and proximity to one another in the night sky. The galaxy gets its name from the constellation Triangulum, where it can be spotted.

The Triangulum Galaxy is sometimes informally referred to as the "Pinwheel Galaxy" by some amateur astronomy references, in some computerized telescope software, and in some public outreach websites.

With a diameter of about 60,000 light-years, the Triangulum galaxy is the third largest member of the Local Group of galaxies, roughly 60% the size of the Milky Way. It may be a gravitationally bound companion of the Andromeda Galaxy. Triangulum may be home to 40 billion stars, compared to 400 billion for the Milky Way, and 1 trillion stars for Andromeda Galaxy.

Taken: October 12, 2019

Telescope: Skywatcher Esprit 80 ED Triplet APO Refractor

Mount: Paramount ME II unguided

Camera: ZWO ASI1600MC-Pro (cooled to -15C; unity gain) Bin 1×1.

Focuser: Starizona Micro Touch Autofocuser

Filters used: Luminance on a ZWO 8 position filter wheel

Exposures: 70×90 sec. for a total exposure time of 1.75 hours; calibrated with 100 bias frames, 30 dark frames, 32 flat frames with 32 dark-flats

Seeing Conditions: Poor due to 98% illuminated moon. Bortle 5 region.

Processed with PixInsight and Photoshop CC 2019