Triangulum is a small constellation in the northern sky. Its name is Latin for "triangle", derived from its three brightest stars, which form a long and narrow triangle. Known to the ancient Babylonians and Greeks, Triangulum was one of the 48 constellations listed by the 2nd century astronomer Ptolemy. The celestial cartographers Johann Bayer and John Flamsteed catalogued the constellation's stars, giving six of them Bayer designations.
The constellation Triangulum as it can be seen by the naked eye.
The peculiar asymmetry of NGC 949.
IC 1727 and UGC 1249.
The Triangulum Galaxy is a spiral galaxy 2.73 million light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC (New General Catalogue) 598. With the D25 isophotal diameter of 18.74 kiloparsecs (61,100 light-years), the Triangulum Galaxy is the third-largest member of the Local Group of galaxies, behind the Andromeda Galaxy and the Milky Way.
Galaxy Messier 33 in Triangulum (the Triangulum Galaxy)
NGC 604 in the Triangulum Galaxy
Composite of about 54 different pointings with Hubble's Advanced Camera for Surveys
Infrared image of M33 taken with the Spitzer Space Telescope