CONSTELLATIONS Essay, Research Paper

Constellations are groupings of the brighter visible stars in the night sky.

Many of these groupings are based on imaginary figures that are seen on the inner

surface of a huge sphere surrounding the earth.

They divide the celestial sphere into 88 constellations, 47 of

which date from ancient times and were listed by the astronomer Ptolemy. The

boundaries are often complex. But all segments of the boundaries lie ease-west

and north-south on the celestial sphere.

Constellations are used today to show general directions in the sky. The constellations may be

divided into three groups: (1) the equatorial constellations,

which lie on each side of the celestial equator, the projection onto the sky of the

earth’s equator; (2) the north circumpolar constellations, which never set for observers

at northern mid-latitudes; and (3) the south circumpolar constellations, which never

set for observers at southern mid-latitudes. The zodiac, widely used in astrology,

consists of 12 constellations through which the orbital motion. The suns yearly

path is called the ecliptic.

The times when given constellations rise and set depends on the time of year

and on the observers position on the earths surface. Constellations also slowly shift

on the celestial sphere’s coordinates because of the precession of the equinoxes and

other movements.. The star Patterns themselves slowly change because of the relative motions of the stars,

but such changes are observable only over immense periods of time.

Some constellations are the Ara{Altar), Aries(Ram), auriga(Charioteer), Andromeda, Canas

Venatici(Hunting Dogs), Canas Major( Big Dog), Canas Minor(Small Dog), Capricornus(Sea Goat),

Carina(Keel), Centaurus(Centaur), Columba(dove) Scorpius(Scorpion). Those are just a few of the many

constellations up in the sky.

One of the 12 original constellations of the zodiac–the band of constellations that lies along the

ecliptic, the apparent yearly path of the sun across the sky. Scorpius is visible in the southern hemisphere

and up the mid-latitudes of the northern hemisphere, where it appears low on the southern horizon. At a

10:00 PM observation of the sky, Scorpius first rises in the east in May, reaches its greatest height in early

July, and drops below the western horizon in late August.

Scorpius actually resembles a scorpion, but it has also been described as a kite. Bright stars

outline a triangular head and trace the constellation’s long, curled tail. Scorpius spans an exceptionally

dense region of the Milky Way and is a rewarding subject for an observation. Its stars clusters are

particularly noteworthy, and some can be seen without a telescope.

Scorpius appears in many legends, particularly those involving the great hunter Orion. In one tale,

the Earth sent the scorpion to sting Orion, who had boasted that he could kill and beast. The scorpion did

not manage to kill him, but Orion fled and dove into the sea. In another story, the Greek god Apollo sent

the scorpion to chase Orion into the sea, as part of plot to keep Orion from Apollo’s sister, The goddess

Artemis. Legends such as these explained why the constellation Orion sinks below the horizon just as the

Scorpius appears.

The star Antares, a red supergiant, is usually considered the heart of the scorpion. The Greeks

named in Antares, meaning “rival to Mars,” probably because the planet has a similar red hue. It is

estimated to be 400 times the diameter of the sun and 9,000 times more luminous. About halfway down the

scorpion’s tail lies a region sometimes called the Table of Scorpius, which is unusually rich in stellar

objects. The double stars Zeta Scorpii 1 and 2 can be identified with the unaided eye in the table. The

scorpions stinger is called Shaula.

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