What is "triangulum"

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 white stars Beta and Gamma Trianguli, of apparent magnitudes 3.00 and 4.00, respectively, form the base of the triangle and the yellow-white Alpha Trianguli, of magnitude 3.41, the apex. Iota Trianguli is a notable double star system, and there are three star systems with known planets located in Triangulum. The constellation contains several galaxies, the brightest and nearest of which is the Triangulum Galaxy or Messier 33—a member of the Local Group. The first quasar ever observed, 3C 48, also lies within Triangulum's boundaries.

Triangulum is a northern constellation.

Triangulum may also refer to:

• Triangulum Minus, an obsolete constellation which is part of Triangulum
• Triangulum Australe, a small southern constellation
• Triangulum Australe (Chinese astronomy)
• Triangulum (Chinese astronomy)
• Triangulum Galaxy, a spiral galaxy visible in Triangulum
• Triangulum II, a dwarf galaxy companion of the Milky Way Galaxy

• USS Triangulum (AK-102), a US Navy cargo ship
• The "Triangulum" story arc, an arc found in Shin Megami Tensei: Devil Survivor 2
• Triangulum (species), species by the name 'triangulum'

According to traditional Chinese uranography, the modern constellation Triangulum is located within the western quadrant of the sky, which is symbolized as the White Tiger of the West (北方玄武, Xī Fāng Bái Hǔ).

The name of the western constellation in modern Chinese is 三角座 (sān jiǎo zuò), meaning "the triangle constellation".

There are several species names which are called "triangulum"; "triangulum" is Latin referring to triangles

• Chaetodon triangulum (C. triangulum), the triangle butterflyfish, a species of fish
• Dendropsophus triangulum (D. triangulum), the triangle treefrog, a species of frog
• Eumorpha triangulum (E. triangulum), a species of moth
• Lampropeltis triangulum (L. triangulum), the milk snake, a species of snake
  • Lampropeltis triangulum triangulum (L. t. triangulum), the eastern milk snake, a subspecies of snake
• Lambula triangulum (L. triangulum), a species of moth
• Noctua triangulum (N. triangulum), a species of moth
• Philanthus triangulum (P. triangulum), the European beewolf, a species of wasp
• Polygonum triangulum (P. triangulum), the bushy knotweed, a species of buckwheat
• Xestia triangulum (X. triangulum), the double square spot, a species of moth