Sabtu, 4 Ogos 2012

A CLEAR VIEW OF THE CONSTELLATION AND STARS FOR A BEGINNER

FCUHOMESCHOOLING ASTRONOMY CLASS

Stars are very hot spheres of gas (usually more than 90% hydrogen) that give off various forms of radiation, including light. The sun is an average-size star. Some stars are much smaller than the sun, others are millions of times bigger. Stars vary in color according to their surface temperature, from blue-white (the hottest at about 35,000 degrees) to white, yellow, orange, to red (the coolest at about 3,000 degrees). Stars are "born" from accumulating physical matter, live out their lives according to how much fuel they have, and then "die" - either by going cold and dark, or exploding (a supernova) when they no longer have the gravity to hold together. From the ejected matter, new stars will eventually be born.

Ordinary eye sight sees about 5,000 stars in a clear night sky. The keenest of the sharp eye sight may see over 7,000 stars. Stars visible with naked eye are called Lucid Stars by the Astronomers. It is believed that there are about 100 billion stars in our own galaxy. The known number of galaxies is about one trillion, each of which may have as much stars as our galaxy on the average. It is then a tremendously enormous number of stars that are present in the known universe.

WELL KNOWN STARS AND CONSTELLATION
There are about 48 old constellations. Today astronomers recognize 88 (44 in each hemisphere) dividing all of the entire sky.

The constellations are totally imaginary things that poets, farmers and astronomers have made up over the past 6,000 years (and probably even more!). The real purpose for the constellations is to help us tell which stars are which, nothing more. On a really dark night, you can see about 1000 to 1500 stars. Trying to tell which is which is hard. The constellations help by breaking up the sky into more managable bits. They are used as mnemonics, or memory aids. For example, if you spot three bright stars in a row in the winter evening, you might realize, "Oh! That's part of Orion!" Suddenly, the rest of the constellation falls into place and you can declare: "There's Betelgeuse in Orion's left shoulder and Rigel is his foot." And once you recognize Orion, you can remember that Orion's Hunting Dogs are always nearby. Then you might recognize the two bright stars in the upper and lower left of the photograph as Procyon in Canis Minor and Sirius in Canis Major, respectively.

Alphabetical listing of constellations

Constellation Families

The Ursa Major Family

The constellation Ursa Major (Great Bear)is certainly one of the most famous constellations; it includes the familiar asterism Big Dipper (the Britsh call it the Plow, the Wain or the Wagon; in German it is known as the "Große Wagen"). Ursa Major is an excellant staring point to explore the night sky.
The group of stars, which form the Ursa Minor, the Little Bear is often called Little Dipper for its form strongly reminds one on an oldfashioned cream ladle or gravy spoon.
One of the very few constellation, who really resembles the figure it was named after, is Draco, the dragon.
The constellation of the Canes Venatici , the Hunting Dogs, consists of two bright stars. A modern view is, that these two "dogs" are hunting the Great Bear.
The Bear Driver Boötes is sometimes called the Herdman. It lies south and east of the Great Bear.
The constellation Coma Berenice has it name after the beautiful Egyptian Queen Berenice, i.e. after the shorn locks.
A wonderful circlet is being formed by Corona Borealis , lying between Boötes and Hercules.
In a region where stars are few the constellation of Camelopardalis (the Giraffe) can be found.
Lynx (the Lynx), likewise in a barren region, forms a sort of fence in front of the Great Bear.
North of the constellation Leo lies the Leo Minor, the Smaller Lion.
The last three constellations are modern astronomical images providing identification for a few fainter stars unattacged to the older groups.

The Zodiacal Family
As the name implies belong to this familiy the twelve constellations of the zodiac. There is a nice rhyme to memorize these constellations.
(One remark here: Actually, nowadays there are two more constellation through which the sun passes along the ecliptic: Ophiuchus and Cetus, the Whale.)
Looking like the king of beasts is the constellation of Leo, the Lion; it forms an arched mane.
South of Coma Berenice lies the group forming Virgo, the Virgin.
The stars of Libra, the Scale, remind of the claws of an old scale.
On the edge of the Milky Way there can be the realistic form of the Scorpius, the Scorpion, be found.
Sagittarius, the Archer, represents a Centaur holding an bow.
Capricorn, The Goat,
Aquarius, the Water Carrier, and
Pisces, the Fishes, occupy a region of the sky which is largely devoted to water creatures of the sea.
According to greek mythology an expedition of the Argonauts went out to get the golden fleece of the Aries, the Ram.
With its long curved horns and its bright red eye (the star Aldebaran) the constellation of Taurus, the Bull, is most impressive in the sky. The Bull moves continuously away from the advancing Hunter Orion.
The Twins Gemini are again a reference to the greek mythology. The both leading stars are named Castor and Pollux after the twin sons of Zeus.
The constellation Cancer, the Crab, is not only part of the Zodiacal Family but as well associated with the Hercules Family.

The Perseus Family
The heavenly W, the constellation Cassiopeia (sometimes called "The Lady of the Chair) is one of those constellations which can be easily found in the northern sky. In the latidude of Central Europe it appears nearly in the zenith.
Cepheus, the royal consort of Cassiopeia, lies to the north and west of the Lady.
Andromeda
The body of Perseus extends approximately parallel to the Milky Way.
Pegasus (see Eridanus).
Like the Cancer the Whale Cetus does not only belong to just one family. It also belongs to the family "Heavenly Waters".
The Charioteer Auriga.
A inconspicuous modern group is that of the Lizard Lacerta. Its lying between Cepheus on the north and Pegasus on the south.
Some nce starfields can be found in the constellation Triangulum, the Triangle.

The Hercules Family
Named after the mythological figure the constellation Hercules shows the strongest man kneeling on the head of draco holding a bow in the hand.
The Arrow Sagitta flies from this bow in the direction of Aquila, Lyra and Cygnus.
The Eagle Aquila.
Lyra, the Lyre, has a distinctive geometrical form consisting of a parallelogram an an equilateral triangle.
The constellation Cygnus, the Swan, is also known as the "Northern Cross".
South of the Swan lies Vulpecula, the Fox.
One of the largest constellations is Hydra, the Sea Serpent.
The modern goup Sextans, the Sextant.
The Cup (of Bacchus ?) Crater and
the Crow Corvus are located between the Sea Serpent and the zodiacal groups Lion and Virgin.
The Serpent Holder Ophiuchus is busily struggling with the
Serpens, the Serpent.
Scutum, the Shield, together with Sagittarius and Centaurus are spectacular to view.
Another creature of the legends about Hercules is the Centaurus.
The group of stars forming the Lupus, the Wolf, seems to have undergone several transformation in history.
The Southern Crown Corona Australis.
The Altar Ara and
the Southern Triangle Triangulum Australis lie on the outhern fringe of the Milky Way.
One of the most conspicous constellations of the southern hemisphere is build from the 4 bright Magnitude stars forming the famous Soutern Cross Crux.

The Orion Family
Followed by his two dogs the giant Orion is struggling against the Bull. Orion is certainly one of the most striking figures in the sky.
The Larger Dog Canis Major.
The Smaller Dog Canis Minor.
Behind Orion there comes the Unicorn, Monoceros galopping towards him.
Located beneath Orion is the small constellation of the Hare, Lepus

The Heavenly Waters
The Doplhin Delphinus and
Equuleus, the Little Horse, are lying between Pegasus and Aquila.
Near the star Rigel (beta Ori) the river Eridanus is flowing toward the bright star Archenar (alpha Eri).
Pisces Austrinus, the Southern Fish.
The great ship Argo has been divided into the following four constellations:
Carina, the Keel.
Puppis, the Stern
Vela, the Sails
Pyxis, the Mariner's Compass.
Near the stern of the ship flies the Dove Columba.

The Bayer Group
The following constellations got their name from the astronomer Johann Bayer (early 17th century). He followed the tradition and gave them names related to sea creatures:
Hydrus, the Water Snake.
Dorado, the Goldfish.
Volans, the Flying Fish.
Apus, the Bird of Paradise.
Pavo, the Peacock.
Grus, the Crane, lying south of the Southern Fish.
Phoenix, the Phoenix.
Tucana, the Toucan.
Indus, the Indian.
South of the Keel lies the Chamaeleon, the Chameleon - extending its tongue to the neighboring minor constellations.
Musca, the Fly. Originally Bayer had designed it as a bee and it was changed somewhen later.

The La Caille Family
In order to fill the star poor regions between the Bayer Group and the other families the astronomer La Caille (well known for his catalog of nebulous objects) conceived the following 13 constellations. He broke with the tradition and gave them scientific names (with one exception: Mensa):
Norma, the Level.
Circinus, the Compasses
Telescopium, the Telescop.
Miscroscope, the Microscope.
Sculptor, the Sculptor's Apparatus.
Fornax, the Furnace.
Caelum, the Graving Tool.
Horologium, the Clock.
Octans, the Octant.
Mensa, the Table Mountain (the Table Mountain at Capetown was the site of La Caille's observatory)n
Reticulum, the Net.
Pictor, the Easel.
Antlia, the Air Pump.

THE GREAT BEAR AND THE SEVEN STARS

Probably the most famous group of stars is the Big Dipper. It is a part of the constellation called Ursa Major. It resembles a bear in many civilizations. The handle of the Dipper is the tail of the bear curving away from the bowl. It has the seven bright stars in it namely, Alkaid, Alcor & Mizar (appear as one), Alioth, Megrez, Phecda, Merak and Dhube. Two of these that form outer wall of the bowl are called the Pointers, directed towards the Polaris when joined in a line from bottom upward

URSA MAJOR

Art Illustration of The Great Bear And The Seven Stars

Description

In Latin Ursa Major means “greater she-bear.” In Greek Arktos is the word for bear, hence the name Arctic, which means bearish and describes the far northern parts of the earth where the Great Bear constellation dominates the heavens even more than in the northern hemisphere. A very large constellation, Ursa Major is best known for its famous asterism or star grouping, the Big Dipper.

Location in the Night Sky
Ursa Major is highest in the sky in the spring and lowest in the autumn, when, according to Indian legends, the Bear is looking for a place to lie down for its winter hibernation. This constellation is a circumpolar constellation, which means it travels closely around the North Star; it is always above the horizon never rising or setting; it can be seen any time of the year, high or low in the sky.
The following graphic shows the position of the Big Dipper in the early evening each season. In the spring the bowl is high above and inverted, pouring water upon the new flowers. In summer the bowl looks as if it is ready to scoop up some cool water with its handle above and its bowl below. In autumn the bowl is right-side-up, ready to catch the falling leaves. In winter the handle points down like an icicle.
The pointer stars in the bowl of the Big Dipper point to Polaris, our current North Star. The distance to Polaris appears to be six times the distance between the pointer stars.

Further studies refer to:
http://www.souledout.org/nightsky/ursamandm/ursamajorandminor.html

THE LITTLE BEAR AND POLARIS:
Five major constellations are always visible above the horizon from our latitudes: Ursa Minor, Ursa Major, Cassiopeia, Cepheus and Draco. They all revolve once in 24 hours around the North Star and stars in these are known as Circumpolar stars. Ursa Minor or the Little Bear is well known for being the host of Polaris, positioned very close to the celestial north pole. Actually the Polaris revolves in radius of 1 degree about the North celestial pole.

Ursa Minor is usually called the Little Dipper. There is also a constellation called Ursa Major, which is called the Big Dipper. In many different myths, the two are bears. In Greek mythology, Hera turned Callisto into a bear because she was jealous of her. Zeus put the bear in the sky along with the Little Bear, which is Callisto's son, Arcas.
The tail of the Little Bear ends with the North Star, Polaris. It is called the North Star because it is at the celestial north pole. Just below the star is a small circle of stars called the "engagement ring". They can be seen using a telescope or binoculars.
To find Polaris, first find the Big Dipper. Imagine a line drawn connecting the right edge of the "bowl". If you keep drawing the line north, it will come to the North Star. Pretty neat!

Polaris is the brightest star in the Ursa Minor. It is part of 7 well known stars similar to Big Dipper. The handle in it curves towards the bowl unlike Big Dipper.

Art Illustration of The Little Bear And The Polaris

Polaris - The North Star or Pole Star

Polaris, more commonly known as The North Star, North Star, or Pole Star, is the closest star to the North Celestial Pole. The following picture provides you a good illustration,

Polaris has been used as the navigation star for centuries in Northern Hemisphere. From an observer point of view, Polaris hangs in the north direction above the horizon as an angle approximately equal to the degree of latitude of the observer. This means that:

If you are standing on the Equator, Polaris will be seen on the horizon in the north direction.
If you are standing on the North Pole, Polaris will be seen directly overhead.
If you are standing on a latitude of 30 degrees, Polaris will be seen 30 degrees off the horizon in the north direction.

Another way to find Polaris by following the line traced from Merak to Dubhe, also known as the Pointers, the two stars at the end of the bowl of the Big Dipper, or Ursa Major, the Great Bear. The following picture provides you a good illustration, http://www.indepthinfo.com:

The Big Dipper is an asterism that makes up part of the constellation of Ursa Major (The Big Bear). It is seen here at the lower left of the image. The Little Dipper, part of the constellation of Ursa Minor (The Little Bear), is seen at the upper right. Polaris, the North Star, is at the end of the handle of the Little Dipper.

CASSIOPEIA

Cassiopeia lies on the other side of the pole from Ursa Major, almost directly opposite the Big Dipper. One can sees the seven stars with naked eyes. Sometimes people visualize it as part of a Crown of the Egyptian queen Cassiopeia, other people see it as an inclined chair or throne.

Art Illustration of The Cassiopeia

Big Dipper to Cassiopeia

The position of stars in the sky

Cassiopeia is a constellation in the northern sky, named after the vain queen Cassiopeia in Greek mythology, who boasted about her unrivalled beauty. Cassiopeia was one of the 48 constellations listed by the 2nd century Greek astronomer Ptolemy, and it remains one of the 88 modern constellations today. It is easily recognizable due to its distinctive 'W' shape, formed by five bright stars. It is bordered by Andromeda to the south, Perseus to the southeast, and Cepheus to the north. She is opposite the Big Dipper, and from northern latitudes can be seen at her clearest in early November

CEPHEUS

Next to Cassiopeia is her husband the king Cepheus, known for some of the well-studied variable stars. Cepheus forms a shape resembling the cap of a clown. Its wedge corner is very close to Polaris and is one of the circumpolar stars. The brightest star in this constellation is called Aldemarin, meaning the arm. It stays close to his queen.

The Art Illustration of Cepheus and his wife, Cassiopeia

DRACO, THE DRAGON
Another famous constellation near the North Pole is Draco meaning Dragon placed beneath the Ursa Minor. It is the dragon that the giant Hercules faces up to. Two known stars in it are called Etamin (tip of Dragon's head) and Thuban in the tail (3rd last star) of the dragon. Etamin is 80 ly away.

The Art Illustration of Draco, the lion.

The position of The Draco Constellation in the sky

THE ORION AND ITS BRIGHT STARS

Next to the Big Dipper, Orion is the most well known constellation of all. Its shape and group of bright stars dominate the winter sky. It contains more bright stars clustered together than any other single group. To the ancients, the figure represented the giant Orion, placed in the heavens, in a heroic gesture holding the shield against Taurus the mighty Bull. The bull on the other hand, with fire darting out from its eye (marked by Aldebaran), is about to charge with its splendid long horns. Orion stands with his right arm holding a great club uplifted in the air, ready to strike. Over his left arm hangs a lion's skin that he holds up as a shield before him to stop the raging bull. With a bit of imagination, it is not difficult to observe in this constellation, a colossal figure and a story behind it.

The Art Illustration of The Orion

The position of the Orion in the sky

Orion contains two of the 1st magnitude bright stars, Betelgeuse and Rigel. Betelgeuse marks the right shoulder or armpit, while Rigel forms the left foot. First, the Betelgeuse rises, pushing its red face. Betelgeuse is a red giant, deep red in color. It is also known as an irregular Variable star, changing its brightness but not regularly.

Rigel appears about 15 to 20 minutes after Betelgeuse. The Celestial equator lies between the two so that Rigel is a southern hemisphere star and Betelgeuse is a northern hemisphere star. With Aldebaran, the two form a triangle, called Winter triangle, dominating the winter sky. Except for Deneb, Rigel (1300 ly) and Betelgeuse (500 ly) are the most distant stars to reach us. Red and cooler the enormous Betelgeuse is 17,000 times brighter than sun. Rigel, blue-white and very hot although smaller than its sisters, nevertheless it is 150,000 times brighter than sun.

The belt of Orion is made of three dazzling stars of 2nd magnitude that are referred to as "bands of Orion," by Job. These lie in a straight line three degrees long. The upper star (actually a double star) of the three forming the belt, lies on the celestial equator. The three stars of Orion's belt are sometimes called "Three kings."

Hanging from the belt is a curved line of 3 stars known as sword of Orion. The central star of the sword is hazy, what is known as the Famous Orion Nebula that exploded out as Supernova. In it lies the cluster of four stars called Orion Trapezium, can only be seen when observed with high resolution spectroscope. The fourth star is called Saiph. It forms one corner of the large approximate trapezium with three other stars - Betelgeuse, Rigel and Bellatrix outlining the Orion's body,. Its location forms the right knee of the mighty hunter. Bellatrix signifies a "Female Warrior." Saiph means sword, the shape of the object obtained by extending from Dagger stars to it.

Orion is in the center of the galaxy that marches in brilliant procession across the winter sky in all its beauty and grandeur, inspiring innumerable admirers throughout ages among host of civilizations. Orion comes into view in October between 9 and 10 p.m. It brings the news of nightly frost of the coming winter.

During November and December, Orion is undoubtedly the most beautiful and dominating constellation in the night sky. In February, one observes it in the southern sky at 9 p.m. In March and April, it is rushing furiously down the western sky. In the middle of May, it is completely gone from the night sky.

BOOTES AND ARCTURUS

The constellation Bootes is in a figure of a Kite in the sky. It rises about 8 O'clock early in March. Bootes is easily located by the very bright star called Arcturus located in the extended arc of the handle of Big Dipper. Arcturus (α Boo) is the brightest star in Boötes and the fourth brightest star in the sky

The position of Bootes Constellation in the sky

AURIGA
Capella, Vega and Arcturus are brightest stars in the northern hemisphere of the sky. Capella is up above the horizon 21 hours. This makes it possible to observe it sometime every night. Capella first appears in the evening in August at about 10 O'clock during first part of the month and stays in the sky until June, always appearing before midnight. In October, it rises almost exactly in the northeast just as the sun is setting.

The Art Illustration of Auriga Constellation

The position of Auriga Constellation

Capella is a giant star yellow in color and 100 times brighter than the sun. Yet, it has the same surface temperature as the sun. It is 46 ly away from us. Never seen separately, it is a binary star, revolving around its companion in 100 days. Wizard spectroscope has made its family secret out. One of 21 bright stars, Capella is in Auriga constellation.

CORONA BOREALIS

The Art Illustration Of The Corona Borealis

The position of The Corona Borealis that is beside The Bootes

Also called Northern Crown, Corona Borealis is a semicircle of stars. Its chief star is called Alphecca, comes into view one and a quarter hours after Arcturus. The group of seven twinkling bright stars is a beautiful sight for observation and enjoyment in the night sky. The entire constellation is only 15 degrees wide.

HERCULES CONSTELLATION

The Hercules Constellation

The position of The Hercules Constellation in the sky

Hercules holds a bow in his outstretched arm. Just shot an arrow to the Dragon or possibly

to the bird nearby. Hercules is located directly north of Scorpius.

FOMALHAUT (Fish) (Pisces Austrinus)

Still lower in the southern sky than Antares, the lonely star Fomalhaut is seen shining brightly. A line joining the Pointers to the pole and extended 120 degrees beyond from the pole, it will reach close to Fomalhaut. This star is at the end of a zigzag line of small twinkling stars that runs across the southern sky in the autumn. The small stars represent the stream of water that Aquarius is pouring from his urn. The stream runs to the southern part of the constellation Piscis Austrinus (Fish). And Fomalhaut means the mouth of the Fish. It rises in Autumn and sinks in December from the night sky. Fomalhaut and Capella rise about the same time. Fomalhaut path is in a short arc. Capella takes more than two and a half hours to rise at its meridian after Fomalhaut sinks. It is one of the four Royal stars of Astrology. Others are Regulus, Antares and Aldebaran. Fomalhaut is never quite one fourth way up towards the zenith from the horizon.

Fomalhaut in Piscis Austrinus

It is the farthest south of all bright stars from our latitudes. It is an autumn star appearing first in August. It gives out 14 times brighter than sun. It is 22 ly away. It does not have a companion star. It is a lone star.

ANDROMEDA AND PEGASUS

Daughter of Queen Cassiopeia and King Cepheus, the beautiful princess is chained to the rock, a curse due to her mother who boasted too much of her beauty. The two constellations Andromeda and Pegasus (the flying horse) are joined by one star at the corner of pegasus square. The two are about 100,000 ly away.

SPICA

The 15th brightest star is Spica that rises not so long after Arcturus. It rises a bit south of exact eastern point in the sky. We can find Spica by extending the arc of the Dipper's handle through Arcturus and about 30 degrees beyond the Arcturus. It can be located by a straight line starting at the pointer nearest Polaris passing diagonally through the bowl of the Dipper about 65 degrees beyond the bottom of the Dipper. It is visible to the naked eye in the middle of March at 8 O'clock in the evening.

Spica does not make a long arc like Arcturus or Capella. It stays south of the celestial equator. It takes 11 hours for Spica to complete its journey setting in the south western horizon. It takes five and a half hours to reach the highest point in the sky about 45 degrees from the zenith in the southern sky in May. It stays in night sky between sunset and midnight during February through early October. In November, December and January, it shows up in the night sky during the time between midnight and dawn. Spica lies in Virgo constellation, close to the ecliptic, which is the apparent annual path of the sun through the heavens.

Its color is bluish white, meaning its surface temperature is greater than sun, Capella and Arcturus. It is 600 times brighter than our sun and 260 ly away from us. Spica is receding from the earth at 1 mile per second. Spica means an ear of wheat. It is seen in the Virgo constellation where a virgin holds a spear of wheat in her hand.

VEGA IN (LYRA CONSTELLATION)

Vega appears about 3 hours after Arcturus in the north eastern horizon. Its color is bluish white sand its surface temperature is less than Spica but much greater than Arcturus or Capella. To find Vega, draw a line from junction of the bowl of the Dipper to the Polaris. Then draw a line from the polaris at right angle extending it about 40 degrees to reach Vega on the same side of Dipper's handle. Vega is on the opposite side of Capella about the pole. Vega has the distinction of being accompanied by four stars in a parallelogram. Vega like Capella is always seen sometime in the night sky during the year. Vega is the main star in the constellation Lyra. Magical Lyre in Orpheus hands gave music that tamed the wild beasts and chained the rivers in their courses.

Early in May, the star Vega rises at the same time that the sun sets and all summer long it is one of the brightest stars in the sky overhead between 9 and 10 O'clock in the evening. It is above the horizon for 18 hours and thus rises in 6 hours after it has set.

Vega is 50 times brighter than sun and 27 ly away. One of the most interesting thing about Vega, is that our sun together with all its planets seemed consistently journeying towards it or nearly towards it in the constellation Lyra. Vega is approaching us at 10 miles per second. Lyra appears as vulture in some old maps. Vega means the "swooping vulture."

DENEB (IN CYGNUS CONSTELLATION)

A little more than hour after Vega has risen, a bright twinkling star appears in the north eastern horizon at point 45 degrees from the pole. It is called Deneb that rises about the same spot on the horizon as Capella. It stays for 20 hours in the sky only obscured by day light.

The highest point a star ever reaches in its daily course is called its meridian. A line drawn from the Polaris to Deneb and to Vega forms a right angle triangle in which Deneb lies at right angle. Deneb lies in the constellation called Cygnus meaning the Swan, an easily identifiable figure of stretched wing flying swan in the sky. Deneb is the brightest star at the head of the figure also called Northern Cross. In the spring when it rises in the north east, the cross is upside down. At setting in the north west, it seems more nearly upright and Deneb at its head sets last of all in the cross. Deneb means "tail" for its position being in the tail section of the constellation. It is sometimes called by its Arabic name Arided meaning the "hindmost."

Deneb is 60,000 times than our sun's actual brightness and 1400 ly away. It is white in color and its surface temperature same as Vega. It is a member of a class of stars called Super Giant for being so large.

Deneb arrives in Spring in the east one hour after Vega. It rises after sunset in middle of May and sets one hour after sunset in early March. The star at the foot of the cross is called Albireo, is a fine double star. One of them is deep blue and the other is bright orange.

In the constellation called Cygnus (Swan), head of Northern Cross, ancients found it in the figure of Flying Swan. Deneb means "the tail", because it appears in the tail section of the constellation Cygnus. It is an Arabic translation of the word Arided meaning "hindmost". It is 60,000 times brighter than sun, 1400 ly away, white in color, of a class of stars called Supergiant, appears in the middle of May (Spring) just after sunset and sets in early part of March one hour after sunset.

The star at the foot of the Cross is called Albireo, a fine double star. One is deep blue and the other is orange, easily visible with the help of ordinary telescope.

ALTAIR (IN AQUILA CONSTELLATION)

About 80 degrees from the pole towards south, halfway between Deneb and Vega, is the brilliantly bright star called Altair. It is 20 degrees directly south from Albireo at the base of the Northern Cross. Altair is seen in the constellation Aquila meaning the eagle. Altair is the middle of the three bright stars in a line. Altair means "the flying eagle." Altair, Vega and Deneb when joined together forms an acute angle triangle known as Summer Triangle, with its short side towards north. Altair at its apex is in the south.

SUMMER TRIANGLE

Altair is in Aquila or the eagle constellation. Altair means the flying eagle.

A brilliantly white (yellowish white) star located by moving down the Cross from Deneb to its tail to Albireo and about 20 degrees more to the first bright star is ALTAIR. About 10 degrees northeast from Altair is the well known Constellation "Dolphinus," also called Job's coffin.

Altair rises about 8 degrees north of the exact eastern point on the horizon. An interesting figure near Altair is in the shape of a diamond with a short tail, lying about 10 degrees northeast of Altair. This group is called Dolphinus. It has a popular name called "Job's coffin."

DELPHINUS

In the shape of a Dolphin, this constellation also called Job's Coffin consists of 5 stars. It contains a variable star, a double star and a spectroscopic binary star.

One seldom sees Altair during the first four months of the year. It takes about 13 hours for Altair to make its journey across the sky. Its color is white or yellowish white. Its surface temperature is less than Vega but greater than Capella. Altair is actually 11 times more luminous than sun and 17 ly away from us. Altair is approaching the earth at a speed of 16 miles per second.

SCORPIUS CONSTELLATION

Constellation Scorpius meaning scorpion that stung the Orion is where Antares can be found. It is considered the hissing snake from which Spenser represents Orion as "flying fast." The mighty hunter Orion does not return to the sky until scorpion is gone. The two Orion and Scorpion never appear together in the sky. The name Antares signifies "Rival of Mars." When the Mars appears in the constellation Scorpius, the two red colored objects are splendid rivals. Antares is a red giant. It is 400 ly away. It is an old star cooler than sun as the red color suggests. Most stars get their energy from fusion of hydrogen atoms into helium. After spending all its hydrogen fuel, the internal core tends to contract, star becomes hotter, for a brief period of its life it lives on secondary sources of energy. The outer layers then swell up and become very luminous. After thousands of years of this spendthrift activity, the secondary sources are exhausted. The star collapses on the inside and explode on the outside, becoming a Nova or a new star. Gravitational forces then attract the fragments back into smaller size feebly shining star of the type known as White Dwarfs, e.g., companion of Sirius.

ANTARES

Antares is at its highest point (meridian) in June 22nd at 10 O'clock in the evening. At its highest point, it is only one quarter way due south from the horizon to the zenith. It is one of the south stars which always lies south of the celestial equator. It appears farther south from Altair.

Antares is one of a binary system. Its companion has a greenish color, not easily seen by small telescopes.

ALDEBARAN

The stars described in Chapter 1 through Chapter 10 earlier, have a particular connection with the spring, summer and autumn months. Capella shines throughout the winter, and in spring and fall as well.

There are however 6 bright stars that are distinctly of the winter. These 6 stars are Aldebaran, Betelgeuse, Regel, Pollux, Procyon and Sirius. Of these 6 stars, Aldebaran is the first to appear in September a bit north of the east point in the horizon. It glows with rosy light, demanding attention proclaiming as one of the most importantly heavenly bodies.

It lies in the open end of a bright V-shaped cluster of stars known as Hyades. The cluster is the head of the well known constellation "Taurus" the bull, named by the Greeks. It is the fiery eye of the enraged bull as he lowers his head charging Orion. The shimmering light of Pleiades can also be shown in the same constellation Taurus.

The meaning of the Arabic word Aldebaran is the "hindmost" or the "follower" of Pleiades, as it appears directly below Pleiades. Aldebaran shines for about 8 months in the sky every year. One hour after the deep ruby red Antares vanishes below the western horizon, another red star Aldebaran rises in eastern horizon. The two never can be seen in the night sky together. The two are named Royal stars in Astrology, a suggestion for royalty.

It is known as a standard 1st magnitude star. It is 70 ly away. At the distance of the sun, it would send 100 times more light than sun. It is receding from us at 30 miles per second from us. It lies in the path of the moon and frequently obscured from our view by moon. Such an intrusion of the moon is called "Occultation," when the subject occulted is a planet or a star. A star disappearing behind the moon shows no sensible disk. A planet gradually disappears. Aldebaran has a faint companion star and belongs to the group of stars called Red Giants. It is a dying star like Antares.

THE TWO DOG STARS: SIRIUS AND PROCYON (IN CANIS MAJOR AND CANIS MINOR)

Moving down the belt of Orion, about 20 degrees south, you meet the brightest star called Sirius, also called the Great Dog Star. It is the chief star of the constellation Canis Major and hence the name. It follows the heels of Orion in its journey in the sky. The constellation names the season dog-days, for the sizzling hot summer days (July and August) in which its presence is made known. During this time, Sirius rises just after the sun in the southern sky. The name Sirius comes from the Greek word scorching (hot summer) or sparkling (excessively & brilliantly bright). Sometimes also called Orion's Dog, Sirius is referred to as brining miseries to men.

Sirius appears in middle of November at 10 O'clock. I March and April it shines in the southwest. It sinks with sun about the end of May.

Sirius is nearer than most bright stars, only 8 and a half ly away. It has a companion star revolving in period of 50 years.

The other Dog star Procyon lies in the constellation Canis Minor. Betelgeuse, Sirius and Procyon form an equilateral triangle, called winter triangle. These three stars together with Rigel form almost square. Procyon is at 11 ly away. It announces the arrival of Sirius the chief. Procyon has companion star revolving at a period of 40 years.

REGULUS

Regulus is known by the shape of a sickle it forms with five other stars.

REGULUS (IN LEO CONSTELLATION)

Regulus appears above the horizon a bit north of the east about 9 O'clock in New Years day or about the Christmas time. It is the chief star of the eastern sky until Arcturus and Vega come into sight. It is a sparkling white star with a slight hint of blue in its color. It takes about 6 and three quarter of an hour to reach the meridian. It shines in January through April in early part of the night sky. It sinks completely in August being at the same place as the sun. It is 140 times brighter than sun and 77 ly away. It is found in the constellation Leo or the Lion (one of Zodiac signs) . The blade of the sickle marks the shoulder of the lion while the Regulus lies at its heart, sometimes named as "heart of the lion." Regulus means "Chief." Sun stays in this constellation a bit more than 5 weeks starting at 2nd week of August. An interesting star in Leo, is the tail of the lion, called Denebola. Denebola points in the direction of another star and thus forms a double star.

SOURCE FROM:

http://www.souledout.org/nightsky/ursamandm/ursamajorandminor.html

http://www2.potsdam.edu/islamma/phys335constellations.htm

http://www.herongyang.com/astrology_horoscope/Polaris_The_North_Pole_Star.html

http://astrooutreach.blogspot.com/2010/11/planetarium-talk-1.html

http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html

http://www.astro.wisc.edu/~dolan/constellations/constellation_list.html
http://maps.seds.org/Const/const_family.html