introductionto constellation

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  • 1. Introduction to Constellations Backyard Astronomy

2. Warm Up 1. 2. 3. 4. 5.What is a constellation? What is a circumpolar constellation? Around what point do all the stars rotate? How do you locate Polaris? Name four things that make stargazing more comfortable? 3. 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. 4. 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. 5. What You Need for Stargazing You dont really need anything, but some things are handy, like Complete darkness-Dont laugh, its not that easy to find. Rural area are slowly being urbanized, bringing their lights with them. Light pollution is a real problem. 6. What You Need: Darkness Darkness means getting away from the city when you can. Crowders Mountain, South Mountain, The Blue Ridge Parkway and several rural spots outside Matthews and Huntersville are still fairly dark. I recommend the Parkway in the Fall and Winter. The quantity of stars you see will take your breath. 7. What You Need: Darkness Darkness means keeping up with the phases of the moon, too. When the moon is waxing past half full, its quite hard to see. 8. What You Need: Star Map/ Planesphere It is handy to have a star map to help get you oriented. We will make one in here, so you get the idea, but laminated ones are nice and they are protected from dew and spilled drinks when your tripping around in the dark. Star Maps are also called planespheres. You can find them in hobby stores for a couple of bucks. 9. What You Need: Flashlight Well, you dont have to trip around in the dark. You can bring a flashlight! Theres one problem here though. It takes your eyes about 20-30 minutes to get acclimated to the dark. Your pupils arent 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. 10. What You Need: Binoculars Binoculars dont 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. 11. What You Need: Telescope? No, you dont 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. 12. What You Need: Warm Clothes Youll 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. 13. Leonid: An Aside I remember the 2002 Leonid meteor shower very well. The Leonid comes in November and that year it was really cold. I got up about 3:30 a.m. (yes, thats right) to have a look. It was incredible. Meteors were streaking across the sky every few seconds. Sometimes several at once. It was the best Leonid for over 35 years. I even woke my wife up to join me. We sat on the deck in sleeping bags and drank coffee. Its one of my happiest memories. Another Leonid of that magnitude is not expected again until 2098 or 2131. 14. Finding Polaris and Why Polaris (or the North Star) is where you want to start. Because Polaris is aligned with the Earths 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. 15. Getting Oriented or Where the Hell is North? Yea, you have to find north. Its where Polaris (or North Star) is. Youll need a compass or major highway to orient yourself. I-77 is good because it runs due north and south. 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. 16. Figuring the Angle Once youve 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 80 higher. Place your other fist on top of your first. Youve now measured 160 up from the horizon. Polaris is located between 250 and 300 above the horizon. Polaris is faint, so look carefully! 17. 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. 18. The Big Dipper 19. The Stars Circling Polaris 20. Now That Youre Oriented, Its Time to Explore. Youre 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. 21. Now That Youre Oriented, Its Time to Explore. You also have access to software that provides you with the same information. 22. Circumpolar Constellations Circum means around (i.e. circumcise, circumnavigate, circumference). Polar refers to the North Pole. Therefore, circumpolar constellations circle Polaris. This makes the 5 circumpolar constellations visible throughout the entire year. Lets look at each! 23. Ursa Minor Once youve located Polaris, youre 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. 24. 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. 25. Ursa Minor 26. 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. 27. Ursa Major 28. Cassiopeia Cassiopeia was the wife of King Cepheus. She was very pretty, and would often boast that she and her daughter were more beautiful than the sea nymphs, the Nereids. They complained to Poseidon, who unleashed a monster onto Cepheus' land. In order to save their country, the king and queen sacrificed their daughter, Andromeda. Just before the monster, named Cetus, ate the princess, Perseus saved her. All five figures are represented in the sky as constellations. 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. 29. Cassiopeia 30. Cepheus Cepheus is one of the oldest constellations in the night sky. This house-shaped constellation is named after an ancient king of a land called Ethiopia (different from the current country, Ethiopia). 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. 31. Cepheus 32. 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. 33. DraCo 34. Signs of the Zodiac Common Constellations 35. Aquarius: The Water Bearer In Greek mythology Aquarius was Ganymede, "cup-bearer to the gods". Alpha Aquarii ("Sadalmelik") and beta Aquarii ("Sadalsuud") are twin supergiants with nearly identical names. The names mean, respectively, "The Lucky One of the King" and "The Luckiest of the Lucky". Gamma Aquarii shares in the good fortune: "Sadachbi