Astronomy Constellations

In the beginning… Ancient cultures organized the sky by linking stars together in patterns. Ancient cultures organized the sky by linking stars together in patterns. Patterns reflected the culture’s beliefs and legends. Patterns reflected the culture’s beliefs and legends. Different cultures gave names to the star to help show the stars’ positions in their pattern. Different cultures gave names to the star to help show the stars’ positions in their pattern. Now: Astronomers use numbers to describe star locations—This has helped to better understand how far stars are and how big the universe is. Now: Astronomers use numbers to describe star locations—This has helped to better understand how far stars are and how big the universe is.

Constellations What are they? What are they? Sections of the sky that contain recognizable star patterns. Sections of the sky that contain recognizable star patterns. In the eye of the beholder… In the eye of the beholder… Different civilizations had different names for the same constellations. ie. Different civilizations had different names for the same constellations. ie.ie.

Constellations Seasonal Changes Seasonal Changes Constellations change from season to season as we go around the sun each year. Constellations change from season to season as we go around the sun each year. This is one reason ancient cultures were able to keep track of the right time of year to plant and harvest their crops. This is one reason ancient cultures were able to keep track of the right time of year to plant and harvest their crops.

**Finding Stars in the Night Sky Altitude Altitude Angle between the object and the horizon. Angle between the object and the horizon. Zenith Zenith Imaginary point in the sky directly above an observer on Earth. Imaginary point in the sky directly above an observer on Earth. Always has an altitude of 90°. Always has an altitude of 90°. Horizon Horizon Line where the sky and the Earth appear to meet. Line where the sky and the Earth appear to meet.

Circumpolar Stars See different stars at different times depending on your location. See different stars at different times depending on your location. The Earth rotates once on its axis each day. The Earth rotates once on its axis each day. Stars near the poles are known as circumpolar. Stars near the poles are known as circumpolar. This means they can be seen at all times of year and all times of night. This means they can be seen at all times of year and all times of night.

Circumpolar Stars near the poles are known as circumpolar. This means they can be seen at all times of year and all times of night.

Circumpolar Constellations: Camelopardus Camelopardus Cassiopeia Cassiopeia Cepheus Cepheus Draco Draco Ursa Major Ursa Major Ursa Minor Ursa Minor

Light Year Time it takes light to travel in one year. 1 light year (ly) = 9.46 trillion kilometers

Asterism Recognizable group of stars that are part of a constellation, but NOT a constellation themselves.

Asterisms to know… Cassiopeia Cassiopeia Little Dipper in Ursa Minor Little Dipper in Ursa Minor Big Dipper in Ursa Major Big Dipper in Ursa Major Orion’s belt in Orion Orion’s belt in Orion The Pleiades in Taurus The Pleiades in Taurus The Sickle in Leo The Sickle in Leo

Orion Greeks saw a hunter. Greeks saw a hunter. Japanese saw a drum. Japanese saw a drum.

Orion Great hunter in Greek mythology. Great hunter in Greek mythology. One of most recognizable patterns of stars in the northern sky. (Winter Constellation) One of most recognizable patterns of stars in the northern sky. (Winter Constellation) Accompanied by his faithful dogs, Canis Major and Canis Minor. Accompanied by his faithful dogs, Canis Major and Canis Minor. Together hunt various celestial animals, including Lepus, the rabbit, and Taurus, the bull. Together hunt various celestial animals, including Lepus, the rabbit, and Taurus, the bull.

The Myth Greek myth: Greek myth: Orion was in love Seven Sisters who form the Pleiades Orion was in love Seven Sisters who form the Pleiades Orion's tragic life ended when he stepped on Scorpius, the scorpion. Orion's tragic life ended when he stepped on Scorpius, the scorpion. Scorpius was placed on the opposite side of the sky so Orion would never be hurt by it again. Scorpius was placed on the opposite side of the sky so Orion would never be hurt by it again.

Orion’s Stars Stars: 1. Betelgeuse-- 12th brightest star in the sky, forms Orion's left shoulder. Reddish in appearance. 1. Betelgeuse-- 12th brightest star in the sky, forms Orion's left shoulder. Reddish in appearance. 2. Rigel—7th brightest star in the sky, blue- white. Located bottom right of Orion, makes up his knee/leg. 2. Rigel—7th brightest star in the sky, blue- white. Located bottom right of Orion, makes up his knee/leg. 3.M42—Orion Nebula—Large glowing cloud of material. Most important part called Orion Molecular Cloud 3.M42—Orion Nebula—Large glowing cloud of material. Most important part called Orion Molecular Cloud 4. Asterism: Orion’s belt 4. Asterism: Orion’s belt

Orion Nebula (M42) Large glowing cloud of material. Large glowing cloud of material. Huge star formation region about 1,500 light years away. Huge star formation region about 1,500 light years away. The most important part of the Orion Nebula is the part we can't see: The opaque Orion Molecular Cloud. This is a huge clump of very cold gas, has mass much greater than Sun. The gas from this cloud slowly collapses due to gravity to form stars. The most important part of the Orion Nebula is the part we can't see: The opaque Orion Molecular Cloud. This is a huge clump of very cold gas, has mass much greater than Sun. The gas from this cloud slowly collapses due to gravity to form stars.

Taurus Taurus is one of the many animals hunted by Orion. Taurus is one of the many animals hunted by Orion. The Greeks saw Taurus as Zeus in disguise. The Greeks saw Taurus as Zeus in disguise. The story went that Zeus fell in love with Europa, the daughter of a king. The story went that Zeus fell in love with Europa, the daughter of a king. On one day while she was playing by the waters edge, she caught sight of a majestic white bull grazing amongst her father’s herd. On one day while she was playing by the waters edge, she caught sight of a majestic white bull grazing amongst her father’s herd. Then she approached the bull, it knelt down and let her get on it's back. Then she approached the bull, it knelt down and let her get on it's back. Once she was on, it sprang to it's feet and took off to the sea in Crete. Once she was on, it sprang to it's feet and took off to the sea in Crete.

1: Aldebaran—the bull’s eye. Double star 1: Aldebaran—the bull’s eye. Double star 2: Pleiades—star cluster 2: Pleiades—star cluster 3. M1—the Crab Nebula. Remnant of a supernova. Spins 33x per second. 3. M1—the Crab Nebula. Remnant of a supernova. Spins 33x per second.

Canis Major the Greater Dog Location Southern Sky Location Southern Sky Myth- Orion Hunting Dog Myth- Orion Hunting Dog 1: Sirius –means “scorching star;” brightest star in the night sky. 1: Sirius –means “scorching star;” brightest star in the night sky.

Canis Minor the Smaller Dog Location Southern Sky Location Southern Sky Myth- Orion Hunting Dog Myth- Orion Hunting Dog 1: Procyon—8 th brightest 1: Procyon—8 th brightest 2: Gomeisa 2: Gomeisa

The Pleiades The seven daughters of Atlas, the titan who holds up the sky. The seven daughters of Atlas, the titan who holds up the sky. The Great Hunter, Orion, fell in love with them and chased them for seven years. The Great Hunter, Orion, fell in love with them and chased them for seven years.

The Pleiades Today there are only six stars that are easily visible with the naked eye. Today there are only six stars that are easily visible with the naked eye. There are many theories about what happened to the 7th one. There are many theories about what happened to the 7th one. Celaeno has often been called the "Lost Pleiad" because she was hit by lightning according to mythology. Celaeno has often been called the "Lost Pleiad" because she was hit by lightning according to mythology. In reality, the star we call Celaeno is just at the limit of human vision in terms of brightness. In reality, the star we call Celaeno is just at the limit of human vision in terms of brightness.

Gemini the Twins Location Zenith Location Zenith Myth-2 brothers- Pollux Immortal and Castor Mortal- Pollux asked to share his immortality with his brother- Jupiter put them in the sky together Myth-2 brothers- Pollux Immortal and Castor Mortal- Pollux asked to share his immortality with his brother- Jupiter put them in the sky together 1. Pollux--Orange 1. Pollux--Orange 2. Castor—white 2. Castor—white

Cancer the Crab Location- Zenith Location- Zenith Myth: Crab was sent to distract Hercules while he was fighting Hydra. Even though he died quickly Hera was grateful Myth: Crab was sent to distract Hercules while he was fighting Hydra. Even though he died quickly Hera was grateful and put his in the sky. 1: M44—The Beehive Cluster 1: M44—The Beehive Cluster

Cassiopeia

Location: Northern Sky Nickname: Rose Colored Cheeks/Queen Cassiopeia

Cassiopeia Myth She was very vain and to learn humility, placed in sky hanging half the time up-side down. She was very vain and to learn humility, placed in sky hanging half the time up-side down. The Queen and King Cepheus are in sky facing each other's feet. The Queen and King Cepheus are in sky facing each other's feet. They cannot speak to each other. Because the Queen insulted the sea nymphs, the pair never set below the surface of the sea. They cannot speak to each other. Because the Queen insulted the sea nymphs, the pair never set below the surface of the sea.

Cassiopeia the Queen An Asterism An Asterism Husband is Cepheus Husband is Cepheus

Cepheus the King Location: Northern Sky Location: Northern Sky Myth King and Queen (Cassiopeia) are never facing each other as punishment because Cassiopeia insulted the Sea Nymphs. They never go below the horizon and touch the water. Myth King and Queen (Cassiopeia) are never facing each other as punishment because Cassiopeia insulted the Sea Nymphs. They never go below the horizon and touch the water. The Fireworks Galaxy—intermediate spiral galaxy The Fireworks Galaxy—intermediate spiral galaxy Circumpolar Circumpolar

Ursa Major Some Native American legends: Some Native American legends: The bowl of the Big Dipper is a giant bear The bowl of the Big Dipper is a giant bear Stars of handle are three warriors chasing it Stars of handle are three warriors chasing it The constellation is low in the sky in autumn evening sky, it was said that the hunters had injured the bear and its blood caused the trees to change color to red. The constellation is low in the sky in autumn evening sky, it was said that the hunters had injured the bear and its blood caused the trees to change color to red.

Big Dipper The asterism in Ursa Major The asterism in Ursa Major 1: Dubhe 1: Dubhe 2: Merak 2: Merak The Big Dipper was very important part of the Underground Railroad The Big Dipper was very important part of the Underground Railroad

Merak Dubhe Mizar Alcor

Ursa Minor Part of Ursa Minor. Part of Ursa Minor. An asterism An asterism The handle of Dipper is Little Bear's tail and Dipper's cup is Bear's flank. The handle of Dipper is Little Bear's tail and Dipper's cup is Bear's flank.

Little Dipper Asterism of Ursa Minor Asterism of Ursa Minor 1: Polaris 1: Polaris Earth's axis is precessing. Polaris is only temporarily at the North Pole. In about 14,000 years, Vega will be the North Star. Earth's axis is precessing. Polaris is only temporarily at the North Pole. In about 14,000 years, Vega will be the North Star. Precession is caused by the gravitational attraction of the Sun and the Moon. It only happens because the Earth is not quite spherical. Precession is caused by the gravitational attraction of the Sun and the Moon. It only happens because the Earth is not quite spherical.

Ursa Minor The most famous star in Ursa Minor is Polaris the North Star. The most famous star in Ursa Minor is Polaris the North Star. Earth's axis is precessing Earth's axis is precessing like a spinning top wobbles around like a spinning top wobbles around Polaris is only temporarily at the North Pole. Polaris is only temporarily at the North Pole. In about 14,000 years, Vega will be the North Star In about 14,000 years, Vega will be the North Star Precession is caused by gravitational attraction of the Sun and the Moon. It only happens because the Earth is not quite spherical. Precession is caused by gravitational attraction of the Sun and the Moon. It only happens because the Earth is not quite spherical.

Leo the Lion A: Regulus (“Little King”) A: Regulus (“Little King”) B: Denebola (Lion’s tail) B: Denebola (Lion’s tail) Asterism: The Sickle (backwards question mark) Asterism: The Sickle (backwards question mark)