Abbreviation:  Tri
English Name:  The Triangle
Genitive: Ras al Muthallath
Hemisphere:  Northern Hemisphere
Location: Between the constellations of Aries and Andromeda.
Visible between latitudes:  
+90 and -50 degrees
Best season: Autumn/Winter
Seen in three seasons: Autumn, Winter and Spring
Best seen in:  Late October / Early December
Seen between: October and December
Right Ascension (RA):  02 hour
Declination (DEC):  +30 degrees
Area (square degrees):  132 (78th)

Triangulum  (The Triangle)

  • Small, but easily found constellation between Andromeda and Aries.
  • The famous galaxy - `The Triangulum Galaxy` at magnitude +5.8, it is bright enough to be seen by the naked eye under the darkest skies, but under light-polluted skies, it is challenging or invisible even in a small telescope or binoculars.

Messier Objects

  • M33  –  Spiral Galaxy; also known as `The Pinwheel Galaxy` or `The Triangulum Galaxy`, face-on with a low surface brightness, making it far more difficult to see than M31 (Andromeda Galaxy) in the constellation of Andromeda.  It is best observed in binoculars and a larger telescopes from 8-inch or more, are required to detect NGC 604 – Emission Nebula (See below for more NGC 604’s details.)

Features of Interest

  • NGC 604  –  Emission Nebula; one of the largest known seething of star birth in M33, The Pinwheel Galaxy.

Named Stars

  • Alpha Tri  (Ras al Muthallath)


  • Photo of the constellation; Triangulum, as it appears to the naked eye. (Lines have been added for clarity.)
  • Sky Chart  –  Triangulum
  • List of stars in Triangulum.


Back to The 88 Constellations Lists  page.



Comments are closed.