The Summer Triangle

Go outside about half an hour after sunset. One by one, the brightest stars in the sky will start popping out. If you look directly overhead, the first three stars to appear form the asterism known as the Summer Triangle. Even though it's almost autumn, the Summer Triangle is still high overhead at nightfall.

Vega, the star farthest to the west, is the brightest among the three. Altair, towards the south, is the second brightest. Deneb, the one farthest north, is the faintest.

Unlike other asterisms that usually belong to a single constellation, the three stars of the Summer Triangle belong to three different constellations. Vega is the brightest star in the constellation Lyra. Altair is in the constellation Aquila. And Deneb belongs to the constellation Cygnus.

References:

Skywatchers Guide: Summer Triangle helps orientation, observation