This famous asterism is rising earlier as we approach Northern Hemisphere summer. Catch it in the east this evening.
The Summer Triangle is once again visible, marching upward overnight. This familiar asterism is composed of Vega (upper left), Deneb (far left), and Altair (lower middle). Credit: A. Fujii
Now rising in the east after sunset is the famous Summer Triangle, so called because it sits high overhead on summer nights. As we head for the Northern Hemisphere summer solstice later this month, the three stars that make up this asterism will rise earlier and earlier each night.Â
Tonight around 11 P.M. local daylight time you’ll see the Summer Triangle some 30° high in the east. The lowest star, Altair, shines at magnitude 0.8 in Aquila the Eagle. To its upper left is magnitude 1.3 Deneb, which marks the tail of Cygnus the Swan. To the upper right of Deneb is Vega in Lyra the Lyre. At magnitude 0, it is the brightest star in the Summer Triangle and the highest as it is rising. Â
In all, the Summer Triangle covers some 415 square degrees and encompasses a portion of the plane of the Milky Way, our galaxy. The brightest region of the galaxy visible within the Summer Triangle is the Cygnus Star Cloud; also visible is the dark Great Rift, made up of light-blocking dust.
Sunrise: 5:32 A.M.
Sunset: 8:26 P.M.
Moonrise: 3:22 P.M.
Moonset: 2:18 A.M.
Moon Phase: Waxing gibbous (74%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
For a look ahead at more upcoming sky events, check out our full Sky This Week column.Â
