The Birds of Summer

.....One of the problems that can keep people from moving from a peaceful contemplation of a dazzling array of stars to finding the dazzling variety of clusters, nebulae, and galaxies that are surprisingly accessible once you make the shift from seeing the sky as a featureless expanse of stars to recognize patterns that will allow you to find wonders hiding in plain -er- slightly assisted sight.

.....Starting in the summer (but lasting until November), three of the brightest stars in the northern sky form a (duh) triangle that covers much of the sky. This "triangle" that first appears in the "summer" sky is called the Summer Triangle because at some point, astronomers got tired of doing things like grabbing a rough pentagon of fourth magnitude stars and calling it "the giraffe"

.....The three bright stars are in three different constellations because the Summer Triangle really does cover a large selection of the sky, and ancient astronomers invented constellations to be able to break the sky into manageable pieces, so they weren't going to invent constellations that tokk up most of the sky. Well, not more than once, anyways. The three bright stars are Altair, Vega, and Deneb, in the constellations of Aquila, Lyra, and Cygnus (the next three constellations I'll write about), and you can use these to do a bit of traveling into the past. Altair, the southernmost star in the triangle, is about 16.8 light years away. This means that it has taken the light from Altair more than sixteen years of traveling through space. The light that reaches us on Friday left Altair about November 12th, 1993.

.....In the northwest, the brilliant star Vega appears to be a step brighter than Altair, but it is actually giving off more than four and a half times as much light into space than Altair does, but Altair is closer. Vega is 25.3 light years away, which mean that Friday's light from Vega left about May 2nd, 1985.

.....The third star, Deneb, is the faintest of the three as seen from Earth, but it actually gives off more than 60,000 times as much light as the Sun does. If we wanted to move Earth to Deneb and get as much light as we do now, we would have to move the Earth to be seventeen times as far away from Deneb as Pluto is from the Sun. Deneb is more than three thousand light years from our solar system, meaning that the light we see now has been traveling through space since 1218 BC, when Ramses II (the Great) was Pharoah of Egypt, and the Trojan War was going on*.

.....These three constellations will be the next three that I write about, Cygnus the swan, Aquila the Eagle, and Lyra the Lyre ... y'know, since two of these three are birds, and since I have felt no compunction about changing constellations, let go ahead and change Lyra to the Australian Lyre-bird, and have these three as as the birds of the Summer Triangle. There are a couple of small constellations that will also show up: Sagitta the arrow, located inside the Summer Triangle, and Scutum, the shield, which I will discuss along with Aquila the eagle, because Aquila has no Messier objects of its own.

* or at least this falls into the range of time in which the original Trojan War took place.