Ursa Major/ˈɜːrsəˈmeɪdʒər/ (also known as the Great Bear) is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by Ptolemy (second century AD), it remains one of the 88 modern constellations. It can be visible throughout the year in most of the northern hemisphere. Its name, Latin for "the greater (or larger) she-bear", stands as a reference to and in direct contrast with Ursa Minor, "the smaller she-bear", with which it is frequently associated in mythology and amateur astronomy. The constellation's most recognizable asterism, a group of seven relatively bright stars commonly known as the "Big Dipper", "the Wagon" or "the Plough" (among others), both mimics the shape of the lesser bear (the "Little Dipper") and is commonly used as a navigational pointer towards the current northern pole star, Polaris in Ursa Minor. The Big Dipper and the constellation as a whole have mythological significance in numerous world cultures, usually as a symbol of the north.
The "Big Dipper" (a term mainly used in the United States and Canada; Plough and (historically) Charles' Wain are used in the United Kingdom, Großer Wagen in Germany and Saptarshi in India) asterism within Ursa Major is made up of seven bright stars (six of them of the second magnitude or higher) that together comprise one of the best-known patterns in the sky. Like many of its common names allude to, its shape is said to resemble either a ladle, an agricultural plough or wagon; in the context of Ursa Major, they are commonly drawn to represent the hindquarters and tail of the Great Bear. Starting with the "ladle" portion of the dipper and extending clockwise (eastward in the sky) through the handle, these stars are the following:
α Ursae Majoris, known by the Arabic name Dubhe ("the bear"), which at a magnitude of 1.79 is the 35th brightest star in the sky and the second brightest of Ursa Major.
β Ursae Majoris, called Merak ("the loins of the bear"), with a magnitude of 2.37.
δ Ursae Majoris, or Megrez, meaning "root of the tail," an appropriate name given its location as the intersection of the body and tail of the bear (or the ladle and handle of the dipper).
ε Ursae Majoris, known as Alioth, a name which refers not to a bear but to a "black horse," the name corrupted from the original and mis-assigned to the similarly named Alcor, the naked-eye binary companion of Mizar. Alioth is the brightest star of Ursa Major and the 33rd brightest in the sky, with a magnitude of 1.76. It is also the brightest of the "peculiar A (Ap) stars," magnetic stars whose chemical elements are either depleted or enhanced, and appear to change as the star rotates.
ζ Ursae Majoris, Mizar, the second star in from the end of the handle of the Big Dipper, and the constellation's fourth brightest star. Mizar, which means "girdle," forms a famous double star, with its optical companion Alcor (80 Ursae Majoris), the two of which were termed the "horse and rider" by the Arabs. The ability to resolve the two stars with the naked eye is often quoted as a test of eyesight, although even people with quite poor eyesight can see the two stars.
The stars Merak (β Ursae Majoris) and Dubhe (α Ursae Majoris) are known as the "pointer stars" because they are helpful for finding Polaris, also known as the North Star or Pole Star. By visually tracing a line from Merak through Dubhe and continuing, one's eye will land on Polaris, accurately indicating true north.
Another asterism known as the "Three Leaps of the Gazelle" is recognized in Arab culture, a series of three pairs of stars found along the southern border of the constellation; From southeast to southwest, the "first leap", comprising ν and ξ Ursae Majoris (Alula Borealis and Australis, respectively); the "second leap", comprising λ and μ Ursae Majoris (Tania Borealis and Australis); and the "third leap", comprising ι and κ Ursae Majoris, (Talitha Borealis and Australis).
The star TYC 3429-697-1 (9h 40m 44s; 48°14’2", located to the east of θ Ursae Majoris and to the southwest of the "Big Dipper") has been recognized as the state star of Delaware, and is informally known as the Delaware Diamond.
M81 is a nearly face-on spiral galaxy 11.8 million light-years from Earth. Like most spiral galaxies, it has a core made up of old stars, with arms filled with young stars and nebulae. Along with M82, it is a part of the galaxy cluster closest to the Local Group.
NGC 3310 is another starburst spiral galaxy located 50 million light-years from Earth. Its bright white color is caused by its higher than usual rate of star formation, which began 100 million years ago after a merger. Studies of this and other starburst galaxies have shown that their starburst phase can last for hundreds of millions of years, far longer than was previously assumed.
NGC 4013 is an edge-on spiral galaxy located 55 million light-years from Earth. It has a prominent dust lane and has several visible star forming regions.
I Zwicky 18 is a young dwarf galaxy at a distance of 45 million light-years. The youngest known galaxy in the visible universe, I Zwicky 18 is about 4 million years old, about one-thousandth the age of the Solar System. It is filled with star forming regions which are creating many hot, young, blue stars at a very high rate.
HD 80606, a sun-like star in a binary system, orbits a common center of gravity with its partner, HD 80607; the two are separated by 1,200 AU on average. Research conducted in 2003 indicates that its sole planet, HD 80606 b is a future hot Jupiter, modeled to have evolved in a perpendicular orbit around 5 AU from its sun. The 4-Jupiter mass planet is projected to eventually move into a circular, more aligned orbit via the Kozai mechanism. However, it is currently on an incredibly eccentric orbit that ranges from approximately one astronomical unit at its apoapsis and six stellar radii at periapsis.
The constellation of Ursa Major has been seen as a bear by many distinct civilizations. This may stem from a common oral tradition stretching back more than 13,000 years. Using statistical and phylogenetic tools, Julien d'Huy reconstructs the following Palaeolithic state of the story: "There is an animal that is a horned herbivore, especially an elk. One human pursues this ungulate. The hunt locates or get to the sky. The animal is alive when it is transformed into a constellation. It forms the Big Dipper".
In Burmese, Pucwan Tārā (pronounced "bazun taja") is the name of a constellation comprising stars from the head and forelegs of Ursa Major; pucwan is a general term for a crustacean, such as prawn, shrimp, crab, lobster, etc.
In Roman mythology, Jupiter (the king of the gods) lusts after a young woman named Callisto, a nymph of Diana. Juno, Jupiter's jealous wife, transforms the beautiful Callisto into a bear. Callisto, while in bear form, later encounters her son Arcas. Arcas almost shoots the bear, but to avert the tragedy, Jupiter turns them into bears and puts them in the sky, forming Ursa Major and Ursa Minor. Callisto is Ursa Major and her son, Arcas, is Ursa Minor. In ancient times the name of the constellation was Helike, ("turning"), because it turns around the Pole. In Book Two of Lucan it is called Parrhasian Helice, since Callisto came from Parrhasia in Arcadia, where the story is set.The Odyssey notes that it is the sole constellation that never sinks below the horizon and "bathes in the Ocean's waves", so it is used as a celestial reference point for navigation. It is also referred to as the "Wain".
One of the few star groups mentioned in the Bible (Job 9:9; 38:32; — Orion and the Pleiades being others), Ursa Major was also pictured as a bear by the Jewish peoples. ("The Bear" was translated as "Arcturus" in the Vulgate and it persisted in the KJV.)
In Finnish language, the asterism is sometimes called with its old Finnish name, Otava. The meaning of the name has been almost forgotten in Modern Finnish; it means a salmonweir. Ancient Finns believed the bear (Ursus arctos) was lowered to earth in a golden basket off the Ursa Major, and when a bear was killed, its head was positioned on a tree to allow the bear's spirit to return to Ursa Major.
The IroquoisNative Americans interpreted Alioth, Mizar, and Alkaid as three hunters pursuing the Great Bear. According to one version of their myth, the first hunter (Alioth) is carrying a bow and arrow to strike down the bear. The second hunter (Mizar) carries a large pot — the star Alcor — on his shoulder in which to cook the bear while the third hunter (Alkaid) hauls a pile of firewood to light a fire beneath the pot.
The Wampanoag people(Algonquian) Native Americans referred to Ursa Major as "maske", meaning "bear" according to Thomas Morton in The New England Canaan.
In Hinduism, Ursa Major is known as Saptarshi, each of the stars representing one of the Saptarshis or Seven Sages viz. Bhrigu, Atri, Angirasa, Vasishta, Pulastya, Pulalaha and Kratu. The fact that the two front stars of the constellations point to the pole star is explained as the boon given to the boy sage Dhruva by Lord Vishnu.
In Javanese, as known as "Bintang Kartika". This name comes from Sanskrit which refers "krttikã" the same star cluster. In ancient Javanese this brightest seven stars are known as Lintang Wuluh, literally means "seven stars". This star clusters so popular because its emergence into the start time marker for planting.
In South Korea, the constellation is referred to as "the seven stars of the north". In the related myth, a widow with seven sons found comfort with a widower, but to get to his house required crossing a stream. The seven sons, sympathetic to their mother, placed stepping stones in the river. Their mother, not knowing who put the stones in place, blessed them and, when they died, they became the constellation.
In Shinto, the 7 largest stars of Ursa Major belong to Amenominakanushi, the oldest and most powerful of all kami.
In China and Japan, the Big Dipper is called the "North Dipper" 北斗 (hokutô), and in ancient times, each one of the seven stars had a specific name, often coming themselves from ancient China:
"Pivot" 樞 (sû) is for Dubhe (Alpha Ursae Majoris)
"Beautiful jade" 璇 (sen) is for Merak (Beta Ursae Majoris)
"Pearl" 璣 (ki) is for Phecda (Gamma Ursae Majoris)
"Authority" 權 (ken) is for Megrez (Delta Ursae Majoris)
"Measuring rod of jade" 玉衡 (gyokkô) is for Alioth (Epsilon Ursae Majoris)
"Opening of the Yang" 開陽 (kaiyô) is for Mizar (Zeta Ursae Majoris)
Alkaid (Eta Ursae Majoris) has several nicknames : "Sword" 劍 (ken) (short form from "End of the sword" 劍先 (ken saki) ), "Flickering light" 搖光 (yôkô), or again "Star of military defeat" 破軍星 (hagun sei), because travel in the direction of this star was regarded as bad luck for an army.
In European star charts, the constellation was visualized with the 'square' of the Big Dipper forming the bear's body and the chain of stars forming the Dipper's "handle" as a long tail. However, bears do not have long tails, and Jewish astronomers considered Alioth, Mizar, and Alkaid instead to be either three cubs following their mother, and the Native Americans as three hunters.
H. A. Rey's alternative asterism for Ursa Major can be said to give it the longer head & neck of a polar bear, as seen in this photo, from the left side.
Noted children's book author H. A. Rey, in his 1952 book The Stars: A New Way to See Them, (ISBN 0-395-24830-2) had a different asterism in mind for Ursa Major, that instead had the "bear" image of the constellation, much as Johannes Hevelius had done (as far as the figure of the bear facing "left"), oriented with Alkaid as the tip of the bear's nose, and the "handle" of the Big Dipper part of the constellation forming the outline of the top of the bear's head and neck, rearwards to the shoulder, potentially giving it the longer head and neck of a polar bear. Because of Rey's book, many amateur astronomers[who?] have come to accept Rey's star chart interpretation of Ursa Major, dropping the idea of the Big Dipper's "handle" as being the hind end of the bear, with a non-natural "tail" extending rearwards.
Ursa Major as depicted in Urania's Mirror, a set of constellation cards published in London c.1825.
Johannes Hevelius drew Ursa Major as if being viewed from outside the celestial sphere.
^Seronik, Gary (July 2012). "M101: A Bear of a Galaxy". Sky & Telescope124 (1).
^Jenniskens, Peter (September 2012). "Mapping Meteoroid Orbits: New Meteor Showers Discovered". Sky & Telescope: 23.
^Laughlin, Greg (May 2013). "How Worlds Get Out of Whack". Sky and Telescope: 29.
^Mallory, J.P.; Adams, D.Q. (August 2006). "Chapter 8.5: The Physical Landscape of the Proto-Indo-Europeans". Oxford Introduction to Proto-Indo-European and the Proto-Indo-European World. Oxford, GBR: Oxford University Press. p. 131. ISBN9780199287918. OCLC139999117. The most solidly ‘reconstructed’ Indo-European constellation is Ursa Major, which is designated as ‘The Bear’ (Chapter 9) in Greek and Sanskrit (Latin may be a borrowing here), although even the latter identification has been challenged.
^The Bansenshukai, written in 1676 by the ninja master Fujibayashi Yasutake, speak several times about these stars, and show a traditional picture of the Big Dipper in his book 8, volume 17, speaking about astronomy and meteorology (from Axel Mazuer's translation).
^Baker, Dr. Douglas The Seven Rays:Key to the Mysteries 1952