CONSTELLATIONS AND THEIR NAMES What is a constellation? . A group of stars that appear to form a picture or pattern in the night sky. We call this the celestial sphere. There are 88 official constellations. When were they named? . Most of the well known constellations were invented before the beginning of recorded history. Stars were named between 500 to 2000 years ago. Who named the stars? . In some regions there is not much differentiation between the seasons. Farmers invented constellations to help remind themselves when to plant and harvest crops. Most were named by the Middle Eastern, Greek and Roman cultures. Why were they named? . Stories were invented to go along with the names as a way of remembering them. Gods, Goddesses, animals and objects were all included in the stories. Some historians believe that this was the invention of Greek and Roman mythology. Native American, Asian, and African cultures also used constellations for ceremonial and religious reasons. Ancient and Modern Constellations 48 “ancient” constellations 38 “modern” constellations . These constellations can . These constellations be seen with the naked needed a telescope to see eye. the dimmer stars. These were all named . Scientists and explorers of before the 1500’s. the 1500’s-1700’s were able to see through the telescope and observe the southern hemisphere. Where does one end and another begin? . The International Astronomical Union (IAU) determined the boundaries between constellations . Eugene Delporte, a Belgian astronomer, acted on behalf of the IAU and published a book call Delimitation Scientifique des Constellations in 1930 . This created precise areas of constellations, not just star patterns in the sky. What is the zodiac? The zodiac is the group of constellations that fall along the plane of the ecliptic (or path the sun appears to trace around the Earth). There are 12 astrological zodiac constellations and 13 astronomical zodiac constellations. The zodiac was used to tell what time of year it was before there were written calendars. A small sampling Some of the constellations that you . There 88 constellations and I can see from your home will explain some of the town have a story to tell. more famous and noteworthy so when you look up, you will know some of them. Orion the Hunter . One of the most recognizable constellations, Orion is depicted raising his club and shield against the charging Taurus. Right arm holds the star Betelgeuse . Left foot holds the star Rigel. Ursa Major: The Great Bear The seven stars of the Big Dipper form the rump and the tail, while the rest is formed from dimmer stars. Two stars in the bowl of the Dipper called Dubhe and Merak (Alpha and Beta Ursae Majoris) are sometimes called the Pointers because when you draw a line through them, they point to the north celestial pole. Dubhe comes from Arabic meaning “the bear”. Merak comes from Arabic meaning “the flank”. Cassiopeia . Cassiopeia was married to King Cepheus and so they lie next to each other in the sky . The only husband/wife pair in the constellations . It has a distinctive “W” shape consisting of five bright stars . Not on any Chinese star charts . She’s said to have been a very conceited and vain queen Cepheus . Lies near the celestial north pole . Contains Delta Cephei which is a pulsating super giant star that varies in brightness every 5.4 days . This is the prototype that astronomers use to estimate distances in space Andromeda . Daughter of Cassiopeia and Cepheus. Poseidon tied her to a rock to be fed to a sea monster and was saved by Perseus. Contains the M31 spiral galaxy located at her right hip. 2.5 million light years away Hercules . The kneeling man . Depicted with his feet towards the north celestial pole, his left foot on the head of the dragon, Draco. His right hand holds a club . Alpha Herculis is a red giant star located at his head . Contains M13, a globular cluster Crux or Southern Cross . Smallest of all 88 constellations . Lies under the hind legs of Centaurus . Contains a dark cloud of dust known as the Coalsack Nebula . Known to the ancient Greeks but lost from view due to precession (gradual drift in the position of the celestial pole against the stars) . Rediscovered by Vespucci in 1501 Lyra . Frequently depicted as both an eagle or vulture and a lyre . Contains Vega . Beta Lyrae is a celebrated variable star . The Ring Nebula lies between Beta and Gamma Lyrae, which is a shell of gas thrown off by a dying star Obsolete Constellations . On many old star maps there . Some astronomers tried to are constellations that are no immortalize their king or longer recognized by government to advance their astronomers careers. Julius Schiller, a German . Because constellations are a astronomer in 1627, tried to product of human introduce Biblical characters imagination, constellations in place of the zodiac…they can be changed over time. were rejected. Conclusion: There are many books available to find out more information on the stars and constellations. I used Ian Ridpath’s Star I have included a small group of Tales. constellations that were interesting The International to me. When I look up into the sky, I Astronomical Union’s want to know what I’m really looking website at www.iau.org. at. Is it just a star or does it belong to And John P. Pratt’s a group? Does it tell a story? Is it a homepage at www.johnpratt.com. normal sized star or a red giant? All images came from Does the constellation contain a Google Images. nebula or another galaxy? On a clear night, the stars are waiting for you to discover them. By Elena Lawrence .