Summer Triangle

Asterism · Northern Hemisphere seasonal name

Three stars, three constellations

Vega, Deneb and Altair form a large triangle that is especially familiar on northern summer evenings. It is a useful observing pattern spanning Lyra, Cygnus and Aquila, rather than a single constellation or mythological creature.

A simple triangle connects three bright stars. Its name describes a northern observing season, not a shape in space shared by the stars.

People around the world have given these stars different figures and stories. This is one interpretation. Lines are recognition aids, rather than official constellation boundaries.

Finding Summer Triangle

Above the horizon. Clear skies and a dark enough view are still needed. The figure’s centre is toward the west in this preview.

Use the bright reference stars below to recognise the shape. A complete drawing can extend outside the current camera window, even when its stars are above the horizon. Open its guide in Sky Timeline to compare the stars with an illustrated interpretation where available.

Bright reference stars

Vega

Magnitude 0.0

Altair

Magnitude 0.8

Lower magnitude numbers mean brighter stars. Clouds, nearby lighting and moonlight change what your eyes can pick out.

Explore another night

Visibility changes with place, season and time. Move through the night to see the object rise, cross the sky and set, while weather remains a separate estimate.