Its atmosphere, composed of roughly half carbon, half oxygen and 2% neon, is devoid of hydrogen and helium—its composition unexplainable by current models of stellar evolution. [47] The star is thought to have undergone a shell helium flash—a point where the shell of helium around the star's core reaches a critical mass and ignites—marked by its abrupt change in variability in 1979. [43] A yellow giant of spectral type G5III,[43] the primary is an RS Canum Venaticorum variable star. Since the medieval period, it has become convenient to use Alpha Ursae Minoris (or "Polaris") as the north star, even though it was still several degrees away from the celestial pole. Polaris, the brightest star in the constellation, is a yellow-white supergiant and the brightest Cepheid variable star in the night sky, ranging from an apparent magnitude of 1.97 to 2.00. Ursa Minor is a medium size constellation located in the far northern reaches of the sky. Others have suggested that an archaic interpretation of Ursa Major was that of a cow, forming a group with Bootes as herdsman, and Ursa Minor as a dog. It is a 'yellow-white' supergiant shining at 2.02 apparent magnitude.It belongs to an unusual class of stars called Cepheid variables. [11] Symbolism: Ursa Minor is also known as ‘The Little Bear’ & ‘The Little Dipper’ as the 7 main stars in the constellation make up a saucepan shape. History & Mythology Ursa Minor is colloquially known in the US as the Little Dipper because its seven brightest stars seem to form the shape of a dipper (ladle or scoop). Ursa Minor contains only 3 stars brighter than magnitude 4. [60], Kochab aside, three more stellar systems have been discovered to contain planets. The star at the end of the dipper handle is Polaris, the North Star.. Polaris is the brightest star in the constellation. Just over 3.5 degrees from the north celestial pole, Delta is a white main-sequence star of spectral type A1V with an apparent magnitude of 4.35,[40] located 172±1 light-years from Earth. URSA MINOR – In this topic, we are going to know and learn about the constellation in the northern sky, the Ursa Minor. This is the list of notable stars in the constellation Ursa Minor, sorted by decreasing brightness. [13], An alternative myth tells of two bears that saved Zeus from his murderous father Cronus by hiding him on Mount Ida. Arcus is about to kill her when Zeus, taking pity, turns him into a bear and places mother and son in the stars as Ursa Major and Ursa Minor. The origin of this name is unclear (Ursa Minor being a "dog's tail" would imply that another constellation nearby is "the dog", but no such constellation is known). For other uses, see, The 41 additional constellations added in the 16th, 17th and 18th centuries, The position of the north celestial pole moves in accordance with the Earth's.  • RA = Right ascension for the Epoch/Equinox J2000.0 This constellation is nearly completely surrounded by the constellation Draco.  • Dist. In Chinese astronomy, the main stars of Ursa Minor are divided between two asterisms: (ly) = Distance in light-years from Earth [50] The combined spectrum of the system is A2V, but the masses of the two component stars are unknown. In another version, Arcas is not turned into a bear and is placed in the sky as Boötes. [19] The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 22 segments (illustrated in infobox). Around 390 light-years distant, it shines with an apparent magnitude of 5.04. It has a Seyfert 2 active galactic nucleus, and is one of the most extreme examples of a Seyfert galaxy. Polaris. Ursa Minor, the Little Bear, is one of the oldest constellations known to the ancient Greeks and is most famous for containing the bright North Star, Polaris. Ursa Minor is one of the 42 constellations that represents an animal. Polaris (Alpha Ursae Minoris), at the end of the Little Dipper’s handle, marks (roughly) the position of the north celestial pole and is the brightest star in Ursa Minor, with a magnitude of 2.0. Other stars of Ursa Minor The second star in the Little Bear’s tail, Delta Ursae Minoris, is called Yildun, a mis-spelling of the Turkish word yildiz meaning ‘star’. The stars here are less bright than those of Ursa Major. Ursa Minor is bordered by Camelopardalis to the west, Draco to the west, and Cepheus to the east. It is also spotted in Ptolemy’s time and thought to be one of the oldest constellations known to the ancient Greeks. Ursa Minor contains the guiding star Polaris. Or more specifically 130.9±0.6 light-years by parallax measurement. [27] Kochab is 450 times more luminous than the Sun and has 42 times its diameter, with a surface temperature of approximately 4,130 K.[28] Estimated to be around 2.95 billion years old, give or take 1 billion years, Kochab was announced to have a planetary companion around 6.1 times as massive as Jupiter with an orbit of 522 days. [44] The northerly nature of the constellation means that the variable stars can be observed all year: the red giant R Ursae Minoris is a semiregular variable varying from magnitude 8.5 to 11.5 over 328 days, while S Ursae Minoris is a long period variable that ranges between magnitudes 8.0 and 11 over 331 days. = absolute magnitude (Mv) While parts of the constellation technically rise above the horizon to observers between the equator and 24°S, stars within a few degrees of the horizon are to all intents and purposes unobservable. • B = Bayer designation. Since ancient times, various peoples have seen the shape of a bear in these stars. Space › Constellations › Ursa Minor › [52] It is a semidetached system, as the secondary star is filling its Roche lobe and transferring matter to the primary. By following a line from the two stars in the end of the bowl of the Big Dipper, Polaris can easily be found. Its parent body is the comet 8P/Tuttle. Nowadays our word Cynosure, from Latin cynosura, from Greek kunosoura, 'dog's tail', is often used just for the Polestar, Polaris, alpha Ursa Minor. It has a planet 4.5 times the mass of Jupiter with one of the most eccentric planetary orbits (with an eccentricity of 0.66), discovered by precisely measuring the radial velocity of the star in 2013. [20][c], Marking the Little Bear's tail,[15] Polaris, or Alpha Ursae Minoris, is the brightest star in the constellation, varying between apparent magnitude 1.97 and 2.00 over a period of 3.97 days. [58] WISE 1506+7027 is a brown dwarf of spectral type T6 that is a mere 11.1+2.3−1.3 light-years away from Earth. Nevertheless, there is a best time of year to observe each of the constellations, even the least conspicuous ones. Ursa Minor is one of the 88 constellations within the celestial sphere. Tales such as these often include the loss of a star, and it is within Hindu cultural memory belief that the stars of Ursa Minor gradually dimmed through history. [56] Ursa Minor has two enigmatic white dwarfs. Instead, the mythographic tradition of Catasterismi makes Cynosura the name of an Oread nymph described as a nurse of Zeus, honoured by the god with a place in the sky. According to some accounts this constellation, Ursa Minor, represents Arcas, son of Callisto and Jupiter. [25] Slightly variable over a period of 4.6 days, Kochab has had its mass estimated at 1.3 times that of the Sun via measurement of these oscillations. Ursa Minor Stars. [45] Located south of Kochab and Pherkad towards Draco is RR Ursae Minoris,[3] a red giant of spectral type M5III that is also a semiregular variable ranging from magnitude 4.44 to 4.85 over a period of 43.3 days. In 2003, it was still two magnitudes brighter than its baseline, and dimming at a rate of 0.02 magnitude a year. The Ursa Minor Dwarf, a dwarf spheroidal galaxy, was discovered by Albert George Wilson of the Lowell Observatory in the Palomar Sky Survey in 1955.  • Var = Variable star designation = visual magnitude (m or mv), also known as apparent magnitude [57] WD 1337+705 is a cooler white dwarf that has magnesium and silicon in its spectrum, suggesting a companion or circumstellar disk, though no evidence for either has come to light. [42], Located close to Polaris is Lambda Ursae Minoris, a red giant of spectral type M1III. Ursa Minor (Latin: "Lesser Bear", contrasting with Ursa Major), also known as the Little Bear, is a constellation in the Northern Sky. One suggestion connects it to the myth of Callisto, with her son Arcas replaced by her dog being placed in the sky by Zeus. Within the constellation of Ursa Minor can be found the North Star, Polaris. Constellation Ursa Major Stars 23 ♋ 00 Ursa Minor is almost entirely represented by its major asterism, the Little Dipper, which starts at Polaris (the North Star) near left center and then swings down and to the right. In the equatorial coordinate system, the right ascension coordinates of these borders lie between 08h 41.4m and 22h 54.0m , while the declination coordinates range from the north celestial pole south to 65.40°. It is a multiple star system that contains at least three individual stars. [22] Located around 432 light-years away from Earth,[23] it is a yellow-white supergiant that varies between spectral types F7Ib and F8Ib,[22] and has around 6 times the Sun's mass, 2,500 times its luminosity and 45 times its radius. Polaris is the brightest Cepheid variable star visible from Earth. How to spot Ursa Minor [48] Z Ursae Minoris is a faint variable star that suddenly dropped 6 magnitudes in 1992 and was identified as one of a rare class of stars—R Coronae Borealis variables. Within Mongol tradition, the stars are identified as seven hunters or brothers. • Name = Proper name. Brown (1899) suggested a non-Greek origin of the name (a loan from an Assyrian An‑nas-sur‑ra "high-rising"). only later, according to Strabo (I.1.6, C3) due to a suggestion by Thales, who suggested it as a navigation aid to the Greeks, who had been navigating by Ursa Major. [53], RW Ursae Minoris is a cataclysmic variable star system that flared up as a nova in 1956, reaching magnitude 6. Its distance has been calculated as 5,000±800 parsecs (16,300 light-years), which puts its location in the galactic halo.  • abs. There are various proposed explanations for the name Cynosura.  • Notes = Common name(s) or alternate name(s); comments; notable properties [for example: multiple star status, range of variability if it is a variable star, exoplanets, etc. Ursa Minor covers 256 square degrees of sky and ranks 56th in size. While the Greeks, Romans, and Native people of the Americas saw bears, other cultures saw a wagon, a plough, a coffin, and many other things. Only lambda and pi remain in use, likely because of their proximity to the north celestial pole. A slight change in the orbital period in 1973 suggests there is a third component of the multiple star system—most likely a red dwarf—with an orbital period of 62.2±3.9 years. [64], Ursa Minor is rather devoid of deep-sky objects. It's brightest star is Polaris at magnitude 1.97. It is listed in the MUL.APIN catalogue, compiled around 1000 BC among the "Stars of Enlil"—that is, the northern sky. Ursa Minor is the 56th largest constellation, occupies a surface area of 256 sq/degrees, and throughout history has been invaluable for navigation as it contains Polaris, also known as the North Star. Allen points to the Old Irish name of the constellation, drag-blod "fire trail", for comparison. "Very recently, however, Brown [Robert Brown, CS1 maint: multiple names: authors list (, "Urania's Mirror c.1825 – Ian Ridpath's Old Star Atlases", Journal of the British Astronomical Association, Proceedings of the American Philosophical Society, "How Did the Constellation of the Bear Receive its Name?  • HD = Henry Draper Catalogue designation number Ursa Minor is listed in the MUL.APIN catalog, compiled around 1000 BC, among the “Stars of Enlil” – the northern sky. Cynosura was a title for the whole constellation of Ursa Minor in classical times. [17] The four stars constituting the bowl of the Little Dipper are of second, third, fourth, and fifth magnitudes, and provide an easy guide to determining what magnitude stars are visible, useful for city dwellers or testing one's eyesight. [9][a] Its New Latin name of stella polaris was coined only in the early modern period. If you stood at the north pole, Polaris would be almost directly overhead. In classical antiquity, the celestial pole was somewhat closer to Beta Ursae Minoris than to Alpha Ursae Minoris, and the entire constellation was taken to indicate the northern direction. [14], Because Ursa Minor consists of seven stars, the Latin word for "north" (i.e., where Polaris points) is septentrio, from septem (seven) and triones (oxen), from seven oxen driving a plough, which the seven stars also resemble. Ursa Minor has traditionally been important for navigation, particularly by mariners, because of Polaris being the north pole star. [26] Bearing the proper name of Yildun, it has around 2.8 times the diameter and 47 times the luminosity of the Sun. [6][7] This name has also been attached to the main stars of Ursa Major. The constellation of Ursa Minor, the Little Bear, is best viewed in Summer during the month of June. Ursa Minor contains one star with a confirmed planet and has no Messier objects. The bears are the constellations known as Ursa Major and Ursa Minor, or the Greater Bear and the Lesser Bear. The stars that make up these constellations are almost always visible in the northern hemisphere. This star has helped civilizations over the years to navigate their way across uncharted seas. [25] Located around 131 light-years away from Earth,[26][d] it is an orange giant—an evolved star that has used up the hydrogen in its core and moved off the main sequence—of spectral type K4III. [12] George William Cox explained it as a variant of Λυκόσουρα, understood as "wolf's tail" but by him etymologized as "trail, or train, of light" (i.e. [8] [73], The Ursids, a prominent meteor shower that occurs in Ursa Minor, peaks between December 18 and 25. It lies… [71], NGC 6251 is an active supergiant elliptical radio galaxy more than 340 million light-years away from Earth. Many stars that form the Little Dipper asterism are former north pole stars, but some will again be north stars. [5], According to Diogenes Laërtius, citing Callimachus, Thales of Miletus "measured the stars of the Wagon by which the Phoenicians sail". Ursa Minor is famous for containing the bright star Polaris that had major role in human history – it has been used for navigating the way across unknown seas. Polaris, the North Star, is the brightest with a visual magnitude of 1.98. Ursa Minor's Stars. It is a spectroscopic binary, with a companion 0.36 AU distant, and a third star—an orange main-sequence star of spectral type K0—8100 AU distant. It is a triple star system, the supergiant primary star having two yellow-white main-sequence star companions that are 17 and 2,400 astronomical units (AU) distant and take 29.6 and 42,000 years respectively to complete one orbit. It is likely to have been a B3 main-sequence star and is now slightly variable. This galaxy may be associated with gamma-ray source 3EG J1621+8203, which has high-energy gamma-ray emission. There is one meteor shower associated with the constellation: … class = Spectral class of the star in the stellar classification system 11 Ursae Minoris is an orange giant of spectral type K4III around 1.8 times as massive as the Sun. The constellation of Ursa Minor is a very important constellation in the night sky since it hosts the famous asterism known as the Little Dipper and also the current north pole star, Polaris. 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