Pegasus, Andromeda tied together

This week, Starwatch is like happy hour. I have a two-for-one deal for you. I want to tell you about two constellations — Pegasus the Winged Horse and Andromeda the Princess. They're literally joined at the tail of the great flying horse.

As it is with a lot of constellations, there are multiple ways to picture them in the night sky.

Traditionally, Pegasus the Winged Horse is seen as a horse with wings flying upside down. You can try looking at Pegasus that way, and with enough imagination, you can make it work for you. But I find it a lot easier to see it as an equestrian creature soaring among the stars right-side up. See if you agree with me.

No matter which way you choose to see Pegasus in our Butler skies, the first thing you need to do is look for a giant and distinct square of four stars above the eastern horizon in the early evening.

That's referred to as the Square of Pegasus. Actually, the Great Square of Pegasus looks much more like a giant diamond since it's orientated diagonally. At the corners of the diamond are the moderately bright stars Alpheratz, Algenib, Markab and Scheat. The square, or diamond, outlines the torso of the celestial horse.

As you can see on the diagram, the neck and head of Pegasus sprout above the highest star Scheat, and his double-jointed leg, which actually bends backward, is off Markab on the right corner of the square.

The corner of the square marked by Alpheratz is where Pegasus gets really wild.

There's a bright and distinct arc of stars that curves to the upper left of Alpheratz that outlines the wing of Pegasus. Just above the bright arc of stars is another fainter arc that also curves up to the left and is nearly parallel to the wing stars.

These stars depict another constellation known as Andromeda the Princess, who was tied on the back of Pegasus. How that happened is part of the Greek mythology story of Pegasus and Andromeda that I'll get to in just a bit.

Now, strictly speaking, the bright arc of stars that make up the wing of Pegasus is astronomically part of the constellation Andromeda, but there's no doubt as to how this curved line of stars makes a great horse's wing.

A great tale

The Greek mythology story goes likes this.

Princess Andromeda was the daughter of Cassiopeia and Cepheus, the Queen and King of ancient Ethiopia. Incidentally, Cassiopeia and Cepheus are represented by their own nearby constellations in the high northeastern sky.

The story goes that Cassiopeia had an ego as wide as the Mediterranean, as she often bragged about how beautiful she was. She was a lot like the queen in Snow White. She did the mirror mirror on the wall thing and really ticked off the folks and the gods of Mount Olympus.

That's how she eventually wound up tied to her throne and cast off into the northern skies. She dared to claim she was more beautiful than Hera, the queen of the gods. That's something mortals must never do, even if they are part of a royal family.

Before all that happened, the highly egotistical Cassiopeia was taking a stroll along a beach, bathing her self-proclaimed beauty in the sun. At one point when her head was really swelled up, she turned toward the surf and called out to Poseidon, the god of the sea.

At the top of her lungs, she declared she was far more beautiful than Poseidon's wife and all 10 of his daughters put together.

This was a big, big mistake!

Like most of the godly hierarchy of Greek mythology, Poseidon had an inflated opinion of himself and also possessed a hair trigger temper.

He was absolutely incensed by Cassiopeia's declaration and sought immediate revenge. He found the biggest, baddest amphibious sea monster he could and ordered it to attack ancient Ethiopia and reduce it to ruins. This would be the equivalent to a present day 25 megaton nuclear bomb!

The day after Cassiopeia's verbal blunder, the sea monster was spotted offshore, making slow but steady progress toward the kingdom.

Cassiopeia and Cepheus knew they had to take drastic action.

They consulted a local oracle and told them of their plight. The oracle studied the situation in his mind for a few minutes and came to the conclusion the only way to save the kingdom was for Cassiopeia and Cepheus to sacrifice their daughter, Princess Andromeda, to the oncoming sea monster.

He thought that would satisfy the sea beast sufficiently so that it wouldn't feel the need to trash the kingdom.

It was a horrible thing to do to their daughter, but they had no choice.

Later that day, they invited Andromeda to join them at the beach for some family fun. Little did she know she had a lot more to fear than just a bad sunburn!

As soon as they got to the beach, Cassiopeia and Cepheus chained their child to a rock and hit the road back to town.

It looked like the end for Princess Andromeda, but just in the nick of time, Perseus entered.

He was the older son of Zeus, the king of the gods. He had been sent on a mission by his father to cut off the head of Medusa, another horrible monster that was so ugly that if you looked at it, you turned immediately to stone. All around the countryside folks were being turned into statues and something had to be done!

Anyway, Perseus used the winged shoes of the god Mercury, messenger of the gods, to fly to and from his rescue mission. He also employed the magic shield of Athena, the goddess of wisdom, to shield his view of Medusa and to be able to cut its head off without getting turned to stone.

He was flying back from his mission, towing the severed head of Medusa, when he spotted the gargantuan sea monster closing in on the beautiful Princess Andromeda.

He used his head, and the dead head of Medusa, to save the damsel in distress. He dove toward the sea monster and waved Medusa's head at it, stopping the monster dead in the water. It rolled under the waves like a giant boat anchor. Then the story gets really weird!

Drops of blood from Medusa's head hit the water, magically producing a giant winged horse named Pegasus.

Now, this was no ordinary winged horse. It was born with supernatural intelligence and the ability to talk!

Pegasus flew up to his new master, Perseus, and inquired as to how he could be of service.

Without hesitation, Perseus sent Pegasus down to Andromeda to get her unchained from that boulder. The winged horse quickly landed on the beach, chewed through the chains and towed the princess up to Perseus.

That's when more magic happened. It was love at first sight!

They were married and almost lived happily ever after, except Perseus got killed in a drunken sword fight in a local bar, but that's another story for another Starwatch column.

This whole adventure is captured in the joined constellations we see in our autumn evening skies to enjoy for eons to come!

Just above the constellation Andromeda the Princess is one of the crown jewels of sky, the Andromeda Galaxy, which is two million light-years away.

But I'll have more to say on that later this month in Starwatch.

Next week, though, I want to tell you about the Leonid Meteor Shower that peaks Nov. 17. It could be one of the best meteor showers in years!

Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, "Pennsylvania Starwatch," available at bookstores and at his Web site www.lynchandthestars.com.