Look at Andromeda to See a Great Galaxy: Dim to the Eye but Brilliant to the Inquiring Mind
+ Von Del Chamberlain +
September 23, 1998
"How far can we see," I am often asked. "Depends on where you look, on what is there and what is between here and there," I typically answer. "Come out with me into the autumn night and I will show you something so far away that you see it by light that is two million years old."
This object is nicely placed for viewing in our late September sky. It is the famous Andromeda Galaxy. Even though it is two million light years away, it is one of our near neighbor galaxies. It contains a few billion stars and is similar to our entire Milky Way Galaxy, the giant stellar metropolis we live in. As you go out to look around on these pleasant autumn evenings take a peak at it.
Andromeda is the constellation named for the beautiful daughter of the legendary queen and king of Ethiopia, Cassiopeia and Cepheus. Because Cassiopeia boasted of her exquisite beauty--"even more beautiful than the sea nymphs," she said as she looked into the mirror--Poseidon sent a sea monster to devour people and their herds of animals. The only way this problem could be solved was to sacrifice Cassiopeia's daughter, Andromeda, to the monster, Cetus. As Cetus swam in for his tasty lunch, Perseus came along, just in time, and saved Andromeda. The charming girl and her hero were married, later to be translated into the sky. Cepheus and Cassiopeia are there as well, required to spend half their time upside down as punishment for their cruelty. Cetus is also a constellation, part of this fabled group coming into our evening sky.
Easiest of the group to find is Cassiopeia. An hour after sunset in September she is rising up into the northeast, resembling a sloppy "W" formed by her five brightest stars. Cepheus is next to her almost directly in the north, composed of fainter stars and looking like a church steeple upside down with the top of the steeple to the right of the North Star, Polaris.
Those who have been reading my column might remember my article of last October about the great baseball diamond in the sky formed by stars in the constellation Pegasus. The brighter stars of Andromeda form a line running from "first base" to the northeast beneath Cassiopeia. If you are out on a clear dark autumn night you can use these stars to find one of the most interesting features of the entire sky, the great galaxy in Andromeda. Look directly east to locate the brighter stars of Pegasus forming a square--the baseball diamond. First base is the star at the upper corner farthest north. Locate the chain of stars coming away from first base and go to the second star. Not far above this star you will see a dim star, and another even dimmer one still a bit higher. Look closely just to the upper right of this and you will find a dim blob of light. As you look at it bring binoculars in front of your eyes to see an extended mass of light filling most of the binocular field. You are seeing light that has been moving toward you for the last two million years--the combined light of billions of stars from the famous Andromeda Galaxy.
Just think about what you are seeing! Fossil light beams stream into your eyes that left their source and traveled toward you while mountains were rising, lakes formed and disappeared and modern man developed to eventually migrate into this part of the world. Even though it looks faint, you can actually see it with just your naked eyes if you know where to look. It is unmistakable in binoculars and modern telescopes reveal it in all its glory. It has everything within it we see around us in our own galaxy: clusters of stars, glowing clouds (nebulae) where stars continue to form; and dark lanes of dust blocking light of more distant stars. It probably has planets as well and some of them might be teeming with life. Out there within that giant luminous pin-wheel there might be eyes peering back at us, admiring their nearby great galaxy in whatever constellation they define from the field of stars off in the direction where our Milky Way Galaxy appears in their sky. They, too, would have a milky way of their own, the plane of light formed by so many stars surrounding them.
Long ago, ancient human eyes turned upward to begin the exploration that has become known as astronomy. Early people from around the globe noticed that barely visible spot of light that attracted more and more attention as lenses were invented to lead the way toward giant telescopes used to reveal the nature of the Andromeda Galaxy. Other galaxies were discovered along with a host of additional interesting things that we continue to study in attempt to comprehend ourselves existing in a vast cosmic environment. It all started with eyes attracted to dim and distant objects barley seen but impossible to ignore.
Back to index of Von Del Chamberlain's Astronomy Articles