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Introduction to Constellations Backyard Astronomy
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The Night Sky People have watched the night skies for millions of years. Some just out of curiosity. Some out of boredom. Some looking for portents, either good or bad. However, the one thing that they all saw was that there was a pattern in the way the stars revolved around the heavens.
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The Night Sky You need only to look up for a few hours to begin to see these same patterns yourself. Like the Sun, stars rise in the east and set later in the west. Planets follow this same pattern unless they are in a retrograde period, though these periods are not especially common.
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What You Need for Stargazing You don’t really need anything, but some things are handy, like… Complete darkness-Don’t laugh, it’s not that easy to find. Rural area are slowly being urbanized, bringing their lights with them. Light pollution is a real problem.
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What You Need: Darkness Darkness means getting away from the city when you can.
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What You Need: Darkness Darkness means keeping up with the phases of the moon, too. When the moon is waxing past half full, it’s quite hard to see.
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What You Need: Star Map/ Planesphere It is handy to have a star map to help get you oriented. Star Maps are also called planespheres. You can find them in hobby stores for a couple of bucks.
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What You Need: Flashlight *Bring a Flashlight!! There’s one problem here though. It takes your eyes about 20-30 minutes to get acclimated to the dark. Your pupils aren’t fully dilated until then, so a regular flashlight will never do. Your eyes will have to get acclimated every time you turn it on. *To prevent this, your flashlight should have a red gel to protect your eyes. Red saran wrap with a rubber band works great. It works great for catching night crawlers too.
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What You Need: Binoculars Binoculars don’t have to be very strong to give you a much better, brighter view of the stars. Binoculars have the ability to gather light even at low magnifications. Even 4X ones will make a marked difference in the detail you can see.
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What You Need: Telescope ? No, you don’t need a telescope, though they are fun. Telescopes require a certain amount of sophistication to set up and operate and they are not for everybody. There are some nice models available at affordable costs. The optics are available alone also if you want to build your own.
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What You Need: Warm Clothes You’ll be happy to know that the best time to look at stars is the least popular time of year to be outside, the winter. So, dress warmly. Remember that the nights are longer in the winter.
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Finding Polaris and Why *Polaris (or the North Star) is where you want to start. *Because Polaris is aligned with the Earth’s axis of rotation, it remains fixed, with all the other planets and stars appearing to move around it. * It is the one star that remains fixed at all times.
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Getting Oriented or Where is North? *Yea, you have to find north. It’s where Polaris (or North Star) is. *You’ll need a compass or major landmark
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Figuring the Angle *Once you’ve decided where north is (right ascension), face in that direction. *Next you have to figure declination (up and down). Extend your arm and make a fist. *Put the bottom of your fist on the horizon. The top of your fist is about 8 0 higher. *Place your other fist on top of your first. You’ve now measured 16 0 up from the horizon. Polaris is located between 25 0 and 30 0 above the horizon. Polaris is faint, so look carefully!
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Another way to get oriented… You can make a compass with a needle, magnet and a cup of water. Just rub the needle across a magnet (see your refrigerator) or leave it attached overnight. Then rub the needle across your nose and place it in the cup very gently. It will float. It will turn north.
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Another Way to Find Polaris If all that compass making and angle crap is just too complicated, there is another way to find Polaris. Find the Big Dipper (not a constellation). Most people recognize this asterism. The two stars that form the front of the cup of the dipper define a line pointing to Polaris.
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The Big Dipper
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Now That You’re Oriented, It’s Time to Explore. You’re pointed in the right direction, but what now. Stars and constellations move constantly and seasonally. What am I looking for? What you need is a star map.
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Circumpolar Constellations “Circum” means around. “polar” refers to the North Pole. Circumpolar = Constellations that circle Polaris, because Polaris is located above the North Pole.
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20 A Few Constellations...
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Ursa Minor Once you’ve located Polaris, you’re ready to identify your first constellation. Polaris is the last star located in the handle of the asterism, the Little Dipper. The name of the constellation that contains the Little Dipper is Ursa Minor or Little Bear.
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Ursa Minor Ursa Minor, also called the Little Dipper, is a circumpolar constellation. This means it never sets in the northern sky. The true figure represented by the stars is the Little Bear. There are several mythological stories behind these famous constellations. In Greek myth, Zeus was having an affair with the lovely Callisto. When his wife, Hera, found out she changed Callisto into a bear. Zeus put the bear in the sky along with the Little Bear, which is Callisto's son, Arcas.
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Ursa Minor
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Ursa Major Ursa Major is probably the most famous constellation, with the exception of Orion. Also known as the Great Bear, it has a companion called Ursa Minor, or Little Bear. Everyone living in the Northern Hemisphere has probably spotted the easily recognized portion of this huge constellation. The body and tail of the bear make up what is known as the Big Dipper. Several different cultures saw a big bear in the sky. The ancient Greeks had a few different stories to explain how the animal ended up there. In one story, Hera discovered Zeus was having an affair with Callisto and turned her into a bear. Zeus put her in the sky along with her son, Arcas, who became the Little Bear.
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Ursa Major
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Cassiopeia Cassiopeia has a very distinct shape. She looks like a “W” or “M” in the sky, depending on where she is. Some legends say that Cassiopeia was chained into the sky and sometimes hangs upside-down to remind others not to be so boastful.
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Cassiopeia
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Cepheus Cepheus is one of the oldest constellations in the night sky. This house-shaped constellation is named after an ancient kind of a land called Ethiopia (different from the current country, Ehtopia). He was married to the beautiful Cassiopeia and had a daughter, Andromeda. In Greek Mythology, Cassiopeia boasted that she and her daughter were more beautiful than the Nereids. They complained to the sea god Poseidon, who sent a monster to destroy Cepheus’ land. The king and queen offered their daughter to the monster, but she was saved by Perseus.
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Cepheus
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Draco Draco the dragon, is only present in the Northern Hemisphere, so those living in the Southern Hemisphere will never see this long constellation. The easiest way to spot Draco is by finding his head. It consists of four stars in a trapezoid, burning brightly just north of Hercules. From there, the tail slithers through the sky, eventually ending between the Big and Little Dippers. It can be difficult to trace Draco in the night sky. From the head, follow the body north towards Cepheus. It suddenly shifts south and west, ending up between the two dippers. The end of the constellation is held by Thuban, which was the pole star over 4,000 years ago.
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Draco
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Star Map, locate the 5 circumpolar constellations and trace them with a colored pencil/pen/marker or highlighter.
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