Lyre, Lyre

.....Lyra the lyre is the first of the constellations of the Summer Triangle; a small constellation consisting of a triangle of stars joined to a parallelogram, but easy to find because it contains one of the brightest stars in the sky. The westernmost star in the Summer Triangle is Vega, and when you can see it over the horizon it the fifth brightest star in the sky. (If someone is reading this over your shoulder, they probably made some joke like, "except for the Sun, dude." I'll wait for a second if you choose to slap them.)

(All good? Yeah, I feel better, too.)

.....Vega is actually one of the stars we use to define the "magnitude" scale that defines the brightness of stars. Originally, this system goes back to the Greek astronomer Hipparchus, who defined the brightest stars as "stars of the first rank" and the dimmest stars as "stars of the sixth rank". Now that we can use cameras to measure exactly how much light we receive from a star, it is now possible to be a little bit more precise. Vega and Arcturus (in Boötes) were use to define zero magnitude. In this reconstructed system, stars with a magnitude of 1.00 are bright, stars with a magnitude of 6.00 are just barely visible one a clear, dry, dark night, and the Sun has a visual magnitude of -27.
.....The only stars brighter than Vega are Arcturus (just barely), Sirius (a winter star), and Canopus and Rigil Kentaurus (stars not visible from the middle and upper United States).

.....The second brightest star in Lyra, Sheliak, is special in another way. Like most stars, it does not travel through space on its own, but Sheliak is actually two stars orbiting closely to each other. As I said, most stars travel in pairs (or more), but these two stars are orbiting so closely to each other that the shape of both stars is distorted, and material is apparently escaping out of the "back end" of Sheliak A. Incredibly funky physics, but you can't see anything through a telescope.

.....What you *can* see in a telescope is Epsilon Lyrae, the other star in the triangle at the top of Lyra. This might look a little funny in the star map, and this star in even a good pair of binoculars will be revealed as a pair of stars. If you then look at Epsilon Lyrae in a telescope under high power, each of these stars is revealed as another pair of stars; Epsilon Lyrae is known as the "double-double" star, four stars (two pair) appearing as one.

.....Numerous times in the past, I have shaken loose from the constellations of the past merely held on to because, ooh, the ancient Greeks created all of western civilization, big whoop, so as I proposed in my last post, I'm replacing the lyre with the lyrebird. After all, how many of us own harps in this day an age? I myself only have one CD of harp music. Hey, it was at a concert; support artists, art establishes and maintains the common culture! You like culture, right? (If you are next to someone who answered no, remember, engineers are often helpful to society as well.)

NEXT: Telescopic objects in Lyra