Big Dipper


The Big Dipper or the Plough is a large asterism consisting of seven bright stars of the constellation Ursa Major; six of them are of second magnitude and one, Megrez, of third magnitude. Four define a "bowl" or "body" and three define a "handle" or "head". It is recognized as a distinct grouping in many cultures. The North Star, the current northern pole star and the tip of the handle of the Little Dipper, can be located by extending an imaginary line through the front two stars of the asterism, Merak and Dubhe. This makes it useful in celestial navigation.

Names and places

The constellation of Ursa Major has been seen as a bear, a wagon, or a ladle. The "bear" tradition is Indo-European, but apparently the name "bear" has parallels in Siberian or North American traditions.

Western astronomy

The name "Bear" is Homeric, and apparently native to Greece, while the "Wain" tradition is Mesopotamian.
Book XVIII of Homer's Iliad mentions it as "the Bear, which men also call the Wain". In Latin, these seven stars were known as the "Seven Oxen". Classical Greek mythography identified the "Bear" as the nymph Callisto, changed into a she-bear by Hera, the jealous wife of Zeus.
In Ireland and the United Kingdom, this pattern is known as the Plough. The symbol of the Starry Plough has been used as a political symbol by Irish Republican and left wing movements. Former names include the Great Wain, Arthur's Wain or Butcher's Cleaver. The terms Charles's Wain and Charles his Wain are derived from the still older Carlswæn. A folk etymology holds that this derived from Charlemagne, but the name is common to all the Germanic languages and the original reference was to the churls' wagon, in contrast to the women's wagon,. An older "Odin's Wain" may have preceded these Nordic designations.
In German, it is known as the "Great Wagon" and, less often, the "Great Bear". In Scandinavia, it is known by variations of "Charles's Wagon", but also the "Great Bear". In Dutch, its official name is the "Great Bear", but it is popularly known as the "Saucepan". In Italian, too, it is called the "Great Wagon".
Romanian and most Slavic languages also call it the "Great Wagon". In Hungarian, it is commonly known as "Göncöl's Wagon" or, less often, "Big Göncöl" after a táltos in Hungarian mythology who carried medicine that could cure any disease. In Finnish, the figure is known as :fi:Otava |Otava with established etymology in the archaic meaning 'salmon net', although other uses of the word refer to 'bear' and 'wheel'. The bear relation is claimed to stem from the animal's resemblance to—and mythical origin from—the asterism rather than vice versa.
In Lithuanian, the stars of Ursa Major are known as Didieji Grįžulo Ratai. Other names for the constellation include Perkūno Ratai, Kaušas, Vežimas, and Samtis.

Asian traditions

In traditional Chinese astronomy, which continues to be used throughout East Asia, these stars are generally considered to compose the Right Wall of the Purple Forbidden Enclosure which surrounds the Northern Celestial Pole, although numerous other groupings and names have been made over the centuries. Similarly, each star has a distinct name, which likewise has varied over time and depending upon the asterism being constructed. The Western asterism is now known as the "Northern Dipper" or the "Seven Stars of the Northern Dipper". The personification of the Big Dipper itself is also known as "Doumu" in Chinese folk religion and Taoism, and Marici in Buddhism.
In Vietnam, the colloquial name for the asterism is "Sao Bánh Lái Lớn", contrasted with Ursa Minor, which is known as "Sao Bánh Lái Nhỏ". Although this name has now been substituted by the Sino-Vietnamese "Bắc Đẩu" in everyday speech, many coastal communities in central and southern Vietnam still refer to the asterism as such and use it to navigate when their fishing vessels return from the sea at night.
In Shinto, the seven largest stars of Ursa Major belong to Amenominakanushi, the oldest and most powerful of all kami.
In Malay, it is known as the "Boat Constellation" ; in Indonesian, as the "Canoe Stars".
In Burmese, these stars are known as Pucwan Tārā. Pucwan is a general term for a crustacean, such as prawn, shrimp, crab, lobster, etc.
While its Western name come from the star pattern's resemblance to a kitchen ladle, in Filipino, the Big Dipper and its sister constellation the Little Dipper are more often associated with the tabo, a one-handled water pot used ubiquitously in Filipino households and bathrooms for purposes of personal hygiene.
In the earliest Indian astronomy, the Big Dipper was called "the Bear" in the Rigveda, but was later more commonly known by the name of Saptarishi, "Seven Sages."

Stars

Within Ursa Major the stars of the Big Dipper have Bayer designations in consecutive Greek alphabetical order from the bowl to the handle.
. Mizar and Alcor are at the upper right.
Proper
Name		Bayer
designation		Apparent
magnitude		Distance
Dubheα UMa1.8124
Merakβ UMa2.479
Phecdaγ UMa2.484
Megrezδ UMa3.381
Aliothε UMa1.881
Mizarζ UMa2.178
Alkaidη UMa1.9101

In the same line of sight as Mizar, but about one light-year beyond it, is the star Alcor. Together they are known as the "Horse and Rider". At fourth magnitude, Alcor would normally be relatively easy to see with the unaided eye, but its proximity to Mizar renders it more difficult to resolve, and it has served as a traditional test of sight. Mizar itself has four components and thus enjoys the distinction of being part of an optical binary as well as being the first-discovered telescopic binary and the first-discovered spectroscopic binary.
Five of the stars of the Big Dipper are at the core of the Ursa Major Moving Group. The two at the ends, Dubhe and Alkaid, are not part of the swarm, and are moving in the opposite direction. Relative to the central five, they are moving down and to the right in the map. This will slowly change the Dipper's shape, with the bowl opening up and the handle becoming more bent. In 50,000 years the Dipper will no longer exist as we know it, but be re-formed into a new Dipper facing the opposite way. The stars Alkaid to Phecda will then constitute the bowl, while Phecda, Merak, and Dubhe will be the handle.

Guidepost

Not only are the stars in the Big Dipper easily found themselves, they may also be used as guides to yet other stars. Thus it is often the starting point for introducing Northern Hemisphere beginners to the night sky:
Additionally, the Dipper may be used as a guide to telescopic objects:
The "Seven Stars" referenced in the Bible's Book of Amos may refer to these stars or, more likely, to the Pleiades.
In addition, the asterism has also been used in corporate logos and the Alaska flag.
The seven stars on a red background of the Flag of the Community of Madrid, Spain, are the stars of the Big Dipper Asterism. The same can be said about the seven stars pictured in the bordure azure of the Coat of arms of Madrid, capital city of Spain.
The asterism's prominence on the north of the night sky produced the adjective in Romance languages and English.
The character Dipper Pines from the animated series Gravity Falls is named after the Big Dipper because he has a birthmark on his forehead in the shape of the asterism.