Lyra, a little constellation with many stories
Constellations come in many sizes, shapes, and flavors in our celestial dome. One of the smaller ones is Lyra the Lyre. In case you’re not into ancient musical instruments a lyre is a small U-shaped harp that was played and enjoyed mostly in ancient Greece, but has since fallen out of favor. It’s quite a story as to how the little harp found its way into the heavens and I’ll get to that in just a bit.
About all there is to the constellation Lyra is the bright star Vega, which shines very high in the southeastern sky, with four dimmer stars forming a lopsided rectangle, or parallelogram, just to the lower left of Vega. That’s it, that’s all there is to Lyra. Unless you’re viewing from a site of horrendous light pollution you should be able to spot that lopsided rectangle.
Vega is more than just the bright star Lyra. It’s the third brightest nighttime star we see in Marshall throughout the course of the year. It’s 2 million miles wide, twice the diameter of the sun, and much hotter. It’s 17,000 degrees F at the surface compared to 10,000 degrees for our sun. It also kicks out 50 times more light than our sun. That’s one of the reasons Vega is so bright in our sky. The other is that it’s relatively close to our solar system, a little over 25 light-years away, which equates to 145 trillion miles. Yes, that’s considered close! When you look at Vega you’re seeing it as it was in 1994 when Bill Clinton was President. It takes that long for light to reach Earth! Vega is significant in other ways that I’ll share with you some other time.
If you have a small to moderate telescope, the most interesting celestial treasure to find within the diminutive constellation Lyra is what astronomers call M57, the Ring Nebula. At first glance through a telescope it looks like a fuzzy faint star, but if you look closer and if your scope can gather enough light it will resemble a tiny smoke ring. Astronomers consider it a planetary nebula, but that moniker is a bit misleading. It really doesn’t have anything to do with a planet even though it reminds some folks of Saturn. In fact that’s how it got that name, because when they were discovered in the 18th century telescopes were a lot smaller and not nearly as sophisticated as they are today.
Planetary nebulae are actually stars that are going through their final phases of life before they become retired white dwarfs. Most of their lives stars produce light and energy through a very complicated process called nuclear fusion. The gist of it is that hydrogen atoms deep in the core of stars fuse together to make heavier helium atoms, but in the process a tiny amount of the hydrogen is converted to a tremendous amount of light and other radiation. Eventually a star runs out of hydrogen in its core and helium atoms begin to fuse into carbon and oxygen. The details get a little hairy, but when a star can no longer fuse atoms in its core it begins to collapse in on itself due to gravity. As it does, the star temporarily puffs or burps out shells of its remaining gases as the core shrinks into a white dwarf. Our own sun will go through this in roughly 6 billion years or so, and the remaining white dwarf won’t be much larger than our Earth.
That’s what’s happening right now in the case of the Ring Nebula. That’s our future about 6 billion years from now! The Ring Nebula is over 2,300 light-years away. The light that you see now from this ailing star has taken since the year 300 B.C. just to meet your eyes!
There are many mythology stories about Lyra that vary according to ancient cultures. The Greeks saw it as a small harp that Mercury the messenger of the gods created out of an old tortoise shell. This is gross, but he strung cow guts across the shell that served as strings. Because the Lyre was created out of a tortoise shell Lyra is also sometimes pictured as a small turtle in the heavens.
Mercury’s creation eventually wound up in the hands of the great early Greek musician Orpheus, who learned how to play it so beautifully that even animals and trees would bow when he performed. Eventually Orpheus was killed by a bunch of crazed female fans who were all trying to grab him after one of his concerts at a seaside village. They became angry after he rejected their invitations for romance. Before his own fans did him in, he threw his Lyre into the sea in hopes of rescuing it later. Of course he never got that chance. The chief gods of Mount Olympus had greatly admired Orpheus and had his dismembered body parts buried at the foot of Mount Olympus. They also dispatched a small eagle to fetch his lyre out of the sea and magically place it into the sky as the little harp we see in the summer heavens.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul.