'Summer Triangle' can be seen in the sky this week
'Summer Triangle,' the famous star formation, can be found low in the eastern sky as darkness falls this week.
With summer in full swing in North America, the famous star formation known as the "Summer Triangle" can be found low in the eastern sky as darkness falls this week.
This huge triangle is composed of three of the brightest stars in the sky, each the brightest star in its own constellation. The pattern is nearly isosceles, which means it appears as a triangle with two equal-length sides.
The brightest in the bunch is the bluish-white star Vega in the constellation Lyra (The Lyre). Next up is the yellow-white Altair in Aquila, the Eagle. Finally there is the white star Deneb in the constellation Cygnus, or the Swan. The stars appear in that order, as the twilight sky grows dark. (This graphic shows how to identify the Summer Triangle stars.)
IN PICTURES: Where stars form
When clear skies allow, the Summer Triangle is one of the favorite parts of the sky for most sky watchers, perhaps because of its sheer simplicity in contrast to overabundance of bright stars found in the wintertime sky.
If you are just getting started in astronomy, and especially as you watch for the first stars to come out after sundown during the coming weeks, you are not very likely to confuse the Summer Triangle with anything else.
Page 1 of 5