Bootes, pronounced by most people as Boot-tees, is one of the 66-plus constellations we see in our night skies. It doesn't really look like what it's alleged to be. According to Greek and Roman mythology, Bootes is supposed to resemble a celestial farmer chasing a celestial great bear. That beast is depicted as the famous constellation Ursa Major, better known as the Big Bear. How the farmer got into the sky is quite a soap opera that I'll get to in a bit. Instead of a farmer look for a sideways kite pointing to the left in the eastern sky. The very bright star Arcturus is fixed at the tail of the left leaning kite.
There's no mistaking Arcturus. It's the brightest star in the evening skies right now and the second brightest nighttime star we see through the course of the year. The brightest is Sirius in the winter constellation Canis Major the Big Dog. If you want to be double sure you're looking at Arcturus use the old rule “Arc to Arcturus”. Extend the arc of the Big Dipper's handle beyond the end of the handle and you'll run right into Arcturus.
The Big Dipper, my favorite asterism, is actually part of the official constellation known by its Latin name as Ursa Major, or in English as the Big Bear. Ursa Major is one of the largest constellations in the heavens, and the Big Dipper is the brightest part, making up the rear end and the tail of the bear. This is a great time to see the upside down Big Bear because it's so high in the sky. Even if you're stargazing in a light polluted urban or suburban locale you still have a really good chance to see all of Ursa Major. It will take a bit of work and a little bit of imagination though. I also highly recommend a comfortable lawn chair to lie back on. That will make it much easier on your neck and back!
It has a noticeably orange hue; a calling card that tells astronomers that Arcturus is a cooler star. Other stars come in faded colors but with the naked eye they're hard to see. Take a small telescope or even an average pair of binoculars and scan across any part of the sky and you'll run into stars with various washed out shades of blue, orange, and red. Those faded shades can help you determine hotter stars from relatively cooler stars. Bluer stars are hotter and reddish-orange stars are cooler. It's just like a flame in a campfire. The hottest part of the fire will be the inside blue flames, with the cooler orange flames on the outside, closer to where you roast your marshmallows.
Even with its orange hue, astronomers describe Arcturus as a red giant star, a bloated star that's starting to run out of hydrogen fuel at its core. Stars in the prime of their lives produce energy and light through a process called nuclear fusion.Tremendous gravitational pressure causes hydrogen atoms in a stellar core to ram into each other so hard that they fuse together to form heavier helium atoms. Eventually, over billions of years, stars begin to run out of hydrogen in their cores. That's what happened to Arcturus. The details are a little hairy, but as the hydrogen gets expended the core begins to collapse. That releases tremendous heat that surges into the outer edges of the star, forcing the star to bloat out way beyond its original size.
Arcturus is nearly 22 million miles in diameter, about 25 times that of our sun, but it's relatively cooler than our home star. The sun surface temperature is about 10,000 degrees F. and Arcturus is just under 7000 degrees to the forbidding touch! Badly bloated Arcturus is shining on from over 212 trillion miles away.
One of my favorite constellation stories is how Bootes, the kite-looking farmer found a place in our heavens. Bootes was a divine love child. Demeter, the goddess of agriculture, was Bootes mother. Bootes's dad was a mortal man that Demeter fell in love with. The affair went on for weeks. The romance and passion were so intense that out of it, Bootes was born. Back then it was very shameful for a god or goddess to fall in love with a mortal, much less have a child with them. Demeter had to hide her new half god-half mortal baby boy, so she arranged to have Bootes adopted by a wealthy farm family since he definitely had agricultural blood in him.
Everything was great early on. Bootes had great foster parents and a wonderful older foster brother who taught Bootes how to hunt and fish. Then tragedy struck. Bootes's stepparents were killed in a chariot accident coming home from a New Year's Eve party. Both Bootes and his older brother were drowning in grief. At the reading of the will a few weeks later Bootes's older brother was appointed executor of the will and handled all of the money willed to him and his half-godly little brother. The older brother was dumbfounded by the new cash he had at his disposal, and you know how money can change people. Soon after that he started spending money like a drunken sailor, and within weeks he decided to skip town with all of the loot, leaving his little brother on the farm flat broke!
Bootes was in a jam. He had to run the farm all by himself, which was no easy task back then. All of the tilling and plowing had to done by hand since Bootes couldn't afford to hire workers. He endlessly toiled in the fields. One night in his exhaustion a bright light bulb flashed in his head. Why not spare yourself from this beastly work by using a beast. There were some oxen on his farm that basically laid around all day. Why not put them to work? So Bootes used his natural godly agricultural abilities and ingenuity to design the first plow that could be pulled by oxen instead of people. The payoff was lightning immediate! Plowing and tilling took much less time and was a whole lot easier on backs.
The word spread quickly. Farmers flocked to Bootes and commissioned him to build them ox pulled plows. Bootes was plowing in the dough! He became the richest man around and lived the good life again.
The gods on Mount Olympus, including Bootes's real mother Demeter, heard of Bootes great breakthrough and decided to reward him handsomely. When Bootes was growing older Demeter plucked him from Earth and placed his body among the stars in the constellation we see today. To make him even happier, she set him up in the stars in a place where he can hunt the constellation Ursa Major, the Big Bear, every single night. Bootes has a smile on his celestial face!
Diagram of Bootes...Click here