Asterisms · Asterism · 3 stars across Lyra, Aquila, Cygnus
Asterism
Summer Triangle
The Summer Triangle: Vega, Deneb and Altair, the three bright corners of northern summer nights, straddling the Milky Way.
- Stars
- Vega, Altair, Deneb
- Constellations
- Lyra, Aquila, Cygnus
- Spans
- about 38° of sky
- Highest at midnight
- mid July
History
The name was popularised in the 1950s by the British broadcaster Patrick Moore — although the Austrian astronomer Oswald Thomas had used it in the 1920s.
Look for
Two of the corners are near neighbours; Deneb looks as bright only because it is vastly more powerful and much farther off. Down the middle runs the dark Great Rift in the Milky Way.