The Summer Triangle; or the Autumn Anachronism

Ready to have the easiest time ever finding something in the sky?  Tonight, at 9 PM, go outside and look straight up while facing west.  Near the zenith (top) of the sky in the northern latitudes is a very bright star called Deneb.  It is the brightest star in the constellation of Cygnus, the Swan.  Down and to the west of Deneb is an incredibly bright star.  This star is Vega and tonight, it will be high up in the western sky.  Vega is the brightest star in the constellation of Lyra, the Lyre.  To the left of Vega high in the SSW sky is yet another bright star; this one is called Altair and it is the brightest star in the constellation Aquila, the Eagle.

Facing West, Looking up (Image created using Stellarium)

Don't worry about finding the constellations that house these three stars right now, just locate the stars themselves; it shouldn't be too hard, they are the brightest stars in that area of the sky tonight.  The most difficult to locate will be Altair because it is not as close to Deneb and Vega as those two stars are to each other.  Once you have located those three stars, pat yourself on the back, you have just found the asterism known as the Summer Triangle.  To tell the truth, it's name is not very accurate because you can see it well into November, but "The Summer-Well-Into-Autumn-Triangle" just didn't roll off the tongue very well, so, the Summer Triangle it is.

The reason why I wanted to point out the Summer Triangle to you is because this is a different sort of an asterism than what we have encountered so far.  The other asterisms we have seen (the Big Dipper, the Little Dipper) were recognizable patterns of stars within constellations; but the Summer Triangle is a recognizable pattern made up of stars from different constellations.  So, an asterism is not bound by the borders of constellations but is simply a recognizable pattern of stars in the sky that is not a constellation.  We will see more of this as autumn turns to winter.

Have fun finding the Summer Triangle!  Next time, we are going to talk about the difference between stars and planets in the sky and we will even locate Jupiter in the sky…can you stand the suspense?!  

Until then, be well and keep looking up!