Summer Triangle
The Summer Triangle is a simple group of three bright stars in the northern sky. The corners are Altair in Aquila, Deneb in Cygnus, and Vega in Lyra, the brightest stars in those constellations.
The triangle sits between about +9° and +45° in latitude, so people in most of the Northern Hemisphere and much of the Southern Hemisphere can see it. Inside the triangle lie two small constellations, Sagitta (the Arrow) and Vulpecula (the Fox).
The name and idea of the Summer Triangle became well known in the 20th century, thanks to H. A. Rey and Patrick Moore in the 1950s, though references go back earlier. It has also been called the Great Triangle in German (Grosses Dreieck) and Sommerliches Dreieck.
Culturally, the three stars appear in the Chinese legend of The Cowherd and the Weaver Girl, linked to the Qixi festival and related celebrations. In the mid-20th century, U.S. Air Force navigators sometimes called it the Navigator's Triangle.
Viewed up close, Altair and Vega are bluish-white, nearby A-type stars. Deneb is a blue-white supergiant far away and one of the galaxy’s most luminous stars.
This page was last edited on 3 February 2026, at 15:43 (CET).