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70-677: RV Polarstern (meaning pole star ) is a German research icebreaker of the Alfred Wegener Institute for Polar and Marine Research (AWI) in Bremerhaven , Germany . Polarstern was built by Howaldtswerke-Deutsche Werft in Kiel and Nobiskrug in Rendsburg , was commissioned in 1982, and is mainly used for research in the Arctic and Antarctica . The ship has a length of 118 metres (387 feet) and

140-399: A bright magnitude 2 star aligned approximately with its northern axis that serves as a pre-eminent star in celestial navigation , and a much dimmer magnitude 5.5 star on its southern axis, Polaris Australis (Sigma Octantis). From around 1700 BC until just after 300 AD, Kochab (Beta Ursae Minoris) and Pherkad (Gamma Ursae Minoris) were twin northern pole stars, though neither

210-602: A burner or lamp and would reasonably be described as stella polaris from about the High Middle Ages and onwards, both in Greek and Latin. On his first trans-Atlantic voyage in 1492, Christopher Columbus had to correct for the "circle described by the pole star about the pole". In Shakespeare's play Julius Caesar , written around 1599, Caesar describes himself as being "as constant as the northern star", though in Caesar's time there

280-475: A declination of –82°, meaning it will rise and set daily for latitudes between 8°S and 8°N, and will not rise to viewers north of this latter 8th parallel north . Precession and proper motion mean that Sirius will be a future southern pole star: at 88.4° S declination in the year 66,270 AD; and 87.7° S declination in the year 93,830 AD. Pole stars of other planets are defined analogously: they are stars (brighter than 6th magnitude, i.e. , visible to

350-514: A direct line with the Earth's rotational axis "above" the North Pole —the north celestial pole—Polaris stands almost motionless in the sky, and all the stars of the northern sky appear to rotate around it. Therefore, it makes an excellent fixed point from which to draw measurements for celestial navigation and for astrometry . The elevation of the star above the horizon gives the approximate latitude of

420-541: A distance of 5° from celestial north. Precession will eventually point the north celestial pole nearer the stars in the constellation Hercules , pointing towards Tau Herculis around 18,400 AD. The celestial pole will then return to the stars in constellation Draco (Thuban, mentioned above) before returning to the current constellation, Ursa Minor. When Polaris becomes the North Star again around 27,800 AD, due to its proper motion it then will be farther away from

490-575: A distance of several degrees, in the early medieval period, and numerous names referring to this characteristic as polar star have been in use since the medieval period. In Old English, it was known as scip-steorra ("ship-star") . In the Old English rune poem , the T-rune is apparently associated with "a circumpolar constellation", or the planet Mars. In the Hindu Puranas , it became personified under

560-436: A distant 7° from the pole, never close enough to be taken as marking the pole, while third-magnitude Delta Cygni will be a more helpful pole star, at a distance of 3° from celestial north, around 11,250 AD. Precession will then point the north celestial pole nearer the constellation Lyra , where the second brightest star in the northern celestial hemisphere , Vega , will be a pole star around 14,500 AD, though at

630-490: A hiatus in 1963–1965. This was originally thought to be due to secular redward (a long term change in redshift that causes light to stretch into longer wavelengths, causing it to appear red) evolution across the Cepheid instability strip , but it may be due to interference between the primary and the first- overtone pulsation modes. Authors disagree on whether Polaris is a fundamental or first-overtone pulsator and on whether it

700-479: A parallax for Polaris, but a distance inferred from it is 136.6 ± 0.5  pc (445.5 ly) for Polaris B, somewhat further than most previous estimates and several times more accurate. This was further improved to 137.2 ± 0.3  pc (447.6 ly), upon publication of the Gaia Data Release 3 catalog on 13 June 2022 which superseded Gaia Data Release 2. Polaris is depicted in the flag and coat of arms of

770-403: A pardon by saying, "I am as constant as the northern star/Of whose true-fixed and resting quality/There is no fellow in the firmament./The skies are painted with unnumbered sparks,/They are all fire and every one doth shine,/But there's but one in all doth hold his place;/So in the world" (III, i, 65–71). Of course, Polaris will not "constantly" remain as the north star due to precession , but this

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840-474: A period of 29.59 ± 0.02 years and an eccentricity of 0.608 ± 0.005 . In 2019, a study by R. I. Anderson gave a period of 29.32 ± 0.11 years with an eccentricity of 0.620 ± 0.008 . There were once thought to be two more widely separated components—Polaris C and Polaris D—but these have been shown not to be physically associated with the Polaris system. Polaris Aa, the supergiant primary component,

910-494: A request for bids on the construction of a replacement for Polarstern , but did not award a contract and eventually withdrew the request in early 2020 as it no longer covered current technological demands for a long-term, efficient and economic vessel. On 20 September 2019 Polarstern sailed from Tromsø , Norway, for a 12 to 14 month-long Multidisciplinary drifting Observatory for the Study of Arctic Climate ( MOSAiC ) expedition across

980-446: A table of the first two batches of names approved by the WGSN; which included Polaris for the star α Ursae Minoris Aa. In antiquity, Polaris was not yet the closest naked-eye star to the celestial pole, and the entire constellation of Ursa Minor was used for navigation rather than any single star. Polaris moved close enough to the pole to be the closest naked-eye star, even though still at

1050-542: A very close F6 main-sequence star with a mass of 1.26  M ☉ . Polaris B can be resolved with a modest telescope. William Herschel discovered the star in August 1779 using a reflecting telescope of his own, one of the best telescopes of the time. In January 2006, NASA released images, from the Hubble telescope , that showed the three members of the Polaris ternary system. The variable radial velocity of Polaris A

1120-483: Is 2.5 times brighter today than when Ptolemy observed it, changing from third to second magnitude. Astronomer Edward Guinan considers this to be a remarkable change and is on record as saying that "if they are real, these changes are 100 times larger than [those] predicted by current theories of stellar evolution ". In 2024, researchers led by Nancy Evans at the Harvard & Smithsonian , have studied with more accuracy

1190-454: Is a double-hulled icebreaker. She is operational at temperatures as low as −50 °C (−58 °F). Polarstern can break through ice 1.5 m (4 ft 11 in) thick at a speed of 5 knots (9.3 km/h; 5.8 mph). Thicker ice of up to 3 m (9.8 ft) can be broken by ramming. On 7 September 1991, Polarstern , assisted by the Swedish arctic icebreaker Oden , reached

1260-450: Is a low-amplitude Population I classical Cepheid variable , although it was once thought to be a type II Cepheid due to its high galactic latitude . Cepheids constitute an important standard candle for determining distance, so Polaris, as the closest such star, is heavily studied. The variability of Polaris had been suspected since 1852; this variation was confirmed by Ejnar Hertzsprung in 1911. The range of brightness of Polaris

1330-404: Is barely visible on a clear night , making it less useful for casual navigational or astronomy alignment purposes. It is a yellow giant 294 light years from Earth. Its angular separation from the pole is about 1° (as of 2000 ). The Southern Cross constellation functions as an approximate southern pole constellation, by pointing to where a southern pole star would be. At the equator , it

1400-543: Is called stella maris , the sterre of the see, for he ledeth in the see men that saylle and have shyppemannes crafte. Polaris was associated with Marian veneration from an early time, Our Lady, Star of the Sea being a title of the Blessed Virgin. This tradition goes back to a misreading of Saint Jerome 's translation of Eusebius ' Onomasticon , De nominibus hebraicis (written ca. 390). Jerome gave stilla maris "drop of

1470-506: Is crossing the instability strip for the first time or not. The temperature of Polaris varies by only a small amount during its pulsations, but the amount of this variation is variable and unpredictable. The erratic changes of temperature and the amplitude of temperature changes during each cycle, from less than 50  K to at least 170 K, may be related to the orbit with Polaris Ab. Research reported in Science suggests that Polaris

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1540-523: Is given as 1.86–2.13, but the amplitude has changed since discovery. Prior to 1963, the amplitude was over 0.1 magnitude and was very gradually decreasing. After 1966, it very rapidly decreased until it was less than 0.05 magnitude; since then, it has erratically varied near that range. It has been reported that the amplitude is now increasing again, a reversal not seen in any other Cepheid. The period, roughly 4 days, has also changed over time. It has steadily increased by around 4.5 seconds per year except for

1610-480: Is invisible in light-polluted urban skies. During the 1st millennium BC, Beta Ursae Minoris (Kochab) was the bright star closest to the celestial pole, but it was never close enough to be taken as marking the pole, and the Greek navigator Pytheas in ca. 320 BC described the celestial pole as devoid of stars. In the Roman era , the celestial pole was about equally distant between Polaris and Kochab. The precession of

1680-495: Is only noticeable over centuries. In Inuit astronomy , Polaris is known as Nuutuittuq ( syllabics : ᓅᑐᐃᑦᑐᖅ ). In traditional Lakota star knowledge, Polaris is named "Wičháȟpi Owáŋžila". This translates to "The Star that Sits Still". This name comes from a Lakota story in which he married Tȟapȟúŋ Šá Wíŋ, "Red Cheeked Woman". However, she fell from the heavens, and in his grief Wičháȟpi Owáŋžila stared down from "waŋkátu" (the above land) forever. The Plains Cree call

1750-508: Is possible to see both Polaris and the Southern Cross. The celestial south pole is moving toward the Southern Cross, which has pointed to the south pole for the last 2000 years or so. As a consequence, the constellation is no longer visible from subtropical northern latitudes, as it was in the time of the ancient Greeks . Around 200 BC, the star Beta Hydri was the nearest bright star to the celestial south pole. Around 2800 BC, Achernar

1820-471: Is the closest Cepheid variable to Earth so its physical parameters are of critical importance to the whole astronomical distance scale . It is also the only one with a dynamically measured mass. The Hipparcos spacecraft used stellar parallax to take measurements from 1989 and 1993 with the accuracy of 0.97  milliarcseconds (970 microarcseconds), and it obtained accurate measurements for stellar distances up to 1,000 pc away. The Hipparcos data

1890-471: Is true north; the rest of the time it is displaced eastward or westward, and the bearing must be corrected using tables or a rule of thumb . The best approximation is made using the leading edge of the " Big Dipper " asterism in the constellation Ursa Major. The leading edge (defined by the stars Dubhe and Merak ) is referenced to a clock face, and the true azimuth of Polaris worked out for different latitudes. The apparent motion of Polaris towards and, in

1960-516: The North Pole as the first conventional powered vessels. Both scientific parties and crew took oceanographic and geological samples and had a common tug of war and a football game on an ice floe. In 2001, Polarstern together with USCGC  Healy reached the pole again. She returned for a third time on 22 August 2011. This time she reported the most frequently recurring ice thickness at 0.9 m (2 ft 11 in) compared with 2 m (6 ft 7 in) in 2001. On 2 March 2008, one of

2030-517: The naked eye at night. The position of the star lies less than 1° away from the north celestial pole , making it the current northern pole star . The stable position of the star in the Northern Sky makes it useful for navigation . As the closest Cepheid variable its distance is used as part of the cosmic distance ladder . The revised Hipparcos stellar parallax gives a distance to Polaris of about 433 light-years (133 parsecs ), while

2100-501: The "Star of the Sea" metaphor, saying that Mary is the "Star of the Sea" to be followed on the way to Christ, "lest we capsize amid the storm-tossed waves of the sea." In Mandaean cosmology , the Pole Star is considered to be auspicious and is associated with the World of Light ("heaven"). Mandaeans face north when praying, and temples are also oriented towards the north. On the contrary,

2170-489: The 'A' refers to what is now known to be the Aa/Ab pair. Polaris Aa is an evolved yellow supergiant of spectral type F7Ib with 5.4 solar masses ( M ☉ ). It is the first classical Cepheid to have a mass determined from its orbit. The two smaller companions are Polaris B, a 1.39  M ☉ F3 main-sequence star orbiting at a distance of 2,400  astronomical units (AU), and Polaris Ab (or P),

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2240-512: The 5th century, when it was still removed from the celestial pole by about 8°. It was known as scip-steorra ("ship-star") in 10th-century Anglo-Saxon England , reflecting its use in navigation. In the Vishnu Purana , it is personified under the name Dhruva ("immovable, fixed"). The name stella polaris was coined in the Renaissance, even though at that time it was well recognized that it

2310-668: The Arctic. She settled in an ice floe on 4 October 2019. The aim was drifting with this floe, passing the North pole and eventually reaching open water in the Fram Strait . While stuck in the ice in March 2020, a member of the aircraft team who had not yet joined the ship in the Arctic tested positive for COVID-19 . This resulted in the entire aircraft team being placed in isolation in Germany and caused delays in

2380-520: The Marian Polar Star"), a collection of Marian poetry published by Nicolaus Lucensis (Niccolo Barsotti de Lucca) in 1655. Its name in traditional pre-Islamic Arab astronomy was al-Judayy الجدي ("the kid", in the sense of a juvenile goat ["le Chevreau"] in Description des Etoiles fixes), and that name was used in medieval Islamic astronomy as well. In those times, it was not yet as close to

2450-574: The Polaris' smaller companion orbit using the CHARA Array . During this observation campaign they have succeeded in shooting Polaris features on its surface; large bright places and dark ones have appeared in close-up images, changing over time. Further, Polaris diameter size has been re-measured to 46  R ☉ , using the Gaia distance of 446 ± 1 light-years, and its mass was determined at 5.13  M ☉ . Because Polaris lies nearly in

2520-410: The celestial north pole, on 24 March 2100. Precession will next point the north celestial pole at stars in the northern constellation Cepheus . The pole will drift to space equidistant between Polaris and Gamma Cephei ("Errai") by 3000 AD, with Errai reaching its closest alignment with the northern celestial pole around 4200 AD. Iota Cephei and Beta Cephei will stand on either side of

2590-402: The constellation Ursa Minor, Cynosura (from the Greek κυνόσουρα "the dog's tail"), became associated with the pole star in particular by the early modern period. An explicit identification of Mary as stella maris with the polar star ( Stella Polaris ), as well as the use of Cynosura as a name of the star, is evident in the title Cynosura seu Mariana Stella Polaris (i.e. "Cynosure, or

2660-430: The current star, with stars that will be "near-north" indicators when no North Star exists during the cycle, including each star's average brightness and closest alignment to the north celestial pole during the cycle: Currently, there is no South Pole Star like Polaris , the so-called North Star . Sigma Octantis is the closest near naked-eye star to the south celestial pole, but at apparent magnitude 5.47 it

2730-566: The distance. The next major step in high precision parallax measurements comes from Gaia , a space astrometry mission launched in 2013 and intended to measure stellar parallax to within 25 microarcseconds (μas). Although it was originally planned to limit Gaia's observations to stars fainter than magnitude 5.7, tests carried out during the commissioning phase indicated that Gaia could autonomously identify stars as bright as magnitude 3. When Gaia entered regular scientific operations in July 2014, it

2800-461: The equinoxes takes about 25,770 years to complete a cycle. Polaris' mean position (taking account of precession and proper motion ) will reach a maximum declination of +89°32'23", which translates to 1657" (or 0.4603°) from the celestial north pole, in February 2102. Its maximum apparent declination (taking account of nutation and aberration ) will be +89°32'50.62", which is 1629" (or 0.4526°) from

2870-473: The future, away from the celestial pole, is due to the precession of the equinoxes . The celestial pole will move away from α UMi after the 21st century, passing close by Gamma Cephei by about the 41st century , moving towards Deneb by about the 91st century . The celestial pole was close to Thuban around 2750 BC, and during classical antiquity it was slightly closer to Kochab (β UMi) than to Polaris, although still about 10 ° from either star. It

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2940-459: The naked eye limit needed to serve as a useful indicator of north to an Earth-based observer, resulting in periods of time during the cycle when there is no clearly defined North Star. There will also be periods during the cycle when bright stars give only an approximate guide to "north", as they may be greater than 5° of angular diameter removed from direct alignment with the north celestial pole. The 26,000 year cycle of North Stars, starting with

3010-447: The naked eye under ideal conditions) that most closely coincide with the projection of the planet's axis of rotation onto the celestial sphere. Different planets have different pole stars because their axes are oriented differently. (See Poles of astronomical bodies .) In the medieval period, Polaris was also known as stella maris ("star of the sea", from its use for navigation at sea), as in e.g. Bartholomaeus Anglicus (d. 1272), in

3080-590: The name Dhruva ("immovable, fixed"). In the later medieval period, it became associated with the Marian title of Stella Maris "Star of the Sea" (so in Bartholomaeus Anglicus , c. 1270s), due to an earlier transcription error. An older English name, attested since the 14th century, is lodestar "guiding star", cognate with the Old Norse leiðarstjarna , Middle High German leitsterne . The ancient name of

3150-434: The north celestial pole as it is now, and used to rotate around the pole. It was invoked as a symbol of steadfastness in poetry, as "steadfast star" by Spenser . Shakespeare 's sonnet 116 is an example of the symbolism of the north star as a guiding principle: "[Love] is the star to every wandering bark / Whose worth's unknown, although his height be taken." In Julius Caesar , he has Caesar explain his refusal to grant

3220-430: The northern celestial pole some time around 5200 AD, before moving to closer alignment with the brighter star Alpha Cephei ("Alderamin") around 7500 AD. Precession will then point the north celestial pole at stars in the northern constellation Cygnus . Like Beta Ursae Minoris during the 1st millennium BC, the bright star closest to the celestial pole in the 10th millennium AD, first-magnitude Deneb , will be

3290-602: The observer. In 2018 Polaris was 0.66° (39.6 arcminutes) away from the pole of rotation (1.4 times the Moon disc) and so revolves around the pole in a small circle 1.3° in diameter. It will be closest to the pole (about 0.45 degree, or 27 arcminutes) soon after the year 2100. Because it is so close to the celestial north pole, its right ascension is changing rapidly due to the precession of Earth's axis , going from 2.5h in AD 2000 to 6h in AD 2100. Twice in each sidereal day Polaris's azimuth

3360-588: The platform portal of the Alfred Wegener Institute (AWI) for Polar and Marine Research. The ship plays a central role in German musician Schiller's 2010 album Atemlos ( German for breathless ). A track is titled after the ship. It is also featured in the DVD of the same title, showing the musician's expedition on the vessel. Pole star Currently, Earth's pole stars are Polaris (Alpha Ursae Minoris),

3430-433: The pole than it is now, while in 23,600 BC it was closer to the pole. Over the course of Earth's 26,000-year axial precession cycle, a series of bright naked eye stars (an apparent magnitude up to +6; a full moon is −12.9) in the northern hemisphere will hold the transitory title of North Star. While other stars might line up with the north celestial pole during the 26,000 year cycle, they do not necessarily meet

3500-821: The retrieval of scientific data from around the ship to provide context to the data taken aboard. After 389 days, this 2019 – 2020 arctic expedition successfully ended on 12 October 2020 when the research vessel safely returned to its home port of Bremerhaven, Germany. A revised request for bids for a replacement, reflecting changes in technology since the first was issued, was expected, with Polarstern II possibly ordered in 2022 to enter service in 2026 or 2027. The new vessel could cost over €800m, and could include hybrid diesel-electric propulsion, integrated under-water robotic systems and several helicopter landing options. Current listings of all cruises on board Polarstern as well as associated contents (e.g., tracklines, weekly reports, cruise reports, publications and data) are presented on

3570-494: The sea" as a (false) Hebrew etymology of the name Maria . This stilla maris was later misread as stella maris ; the misreading is also found in the manuscript tradition of Isidore 's Etymologiae (7th century); it probably arises in the Carolingian era ; a late 9th-century manuscript of Jerome's text still has stilla , not stella , but Paschasius Radbertus , also writing in the 9th century, makes an explicit reference to

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3640-469: The south is associated with the World of Darkness . Polaris Polaris is a star in the northern circumpolar constellation of Ursa Minor . It is designated α Ursae Minoris ( Latinized to Alpha Ursae Minoris ) and is commonly called the North Star or Pole Star . With an apparent magnitude that fluctuates around 1.98, it is the brightest star in the constellation and is readily visible to

3710-511: The star had approached the celestial pole to within a few degrees. Gemma Frisius , writing in 1547, referred to it as stella illa quae polaris dicitur ("that star which is called 'polar'"), placing it 3° 8' from the celestial pole. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included

3780-463: The star in Nehiyawewin : acâhkos êkâ kâ-âhcît "the star that does not move" ( syllabics : ᐊᒑᐦᑯᐢ ᐁᑳ ᑳ ᐋᐦᒌᐟ ). In Mi'kmawi'simk the star is named Tatapn . In the ancient Finnish worldview, the North Star has also been called taivaannapa and naulatähti ("the nailstar") because it seems to be attached to the firmament or even to act as a fastener for the sky when other stars orbit it. Since

3850-584: The starry sky seemed to rotate around it, the firmament is thought of as a wheel, with the star as the pivot on its axis. The names derived from it were sky pin and world pin . Many recent papers calculate the distance to Polaris at about 433 light-years (133 parsecs), based on parallax measurements from the Hipparcos astrometry satellite. Older distance estimates were often slightly less, and research based on high resolution spectral analysis suggests it may be up to 110 light years closer (323 ly/99 pc). Polaris

3920-441: The stars' proper motions), the role of North Star has passed from one star to another in the remote past, and will pass in the remote future. In 3000 BC, the faint star Thuban in the constellation Draco was the North Star, aligning within 0.1° distance from the celestial pole, the closest of any of the visible pole stars. However, at magnitude 3.67 (fourth magnitude) it is only one-fifth as bright as Polaris, and today it

3990-475: The successor mission Gaia gives a distance of about 448 light-years (137 parsecs ). Calculations by other methods vary widely. Although appearing to the naked eye as a single point of light, Polaris is a triple star system , composed of the primary, a yellow supergiant designated Polaris Aa, in orbit with a smaller companion, Polaris Ab; the pair is in a wider orbit with Polaris B. The outer pair AB were discovered in August 1779 by William Herschel , where

4060-427: The system in 1929, giving an orbital period of about 29.7 years with an eccentricity of 0.63. This period was confirmed by proper motion studies performed by B. P. Gerasimovič in 1939. As part of her doctoral thesis, in 1955 E. Roemer used radial velocity data to derive an orbital period of 30.46 y for the Polaris A system, with an eccentricity of 0.64. K. W. Kamper in 1996 produced refined elements with

4130-473: The translation of John Trevisa (1397): by the place of this sterre place and stedes and boundes of the other sterres and of cercles of heven ben knowen: therefore astronomers beholde mooste this sterre. Then this ster is dyscryved of the moste shorte cercle; for he is ferre from the place that we ben in; he hydeth the hugenesse of his quantite for unmevablenes of his place, and he doth cerfifie men moste certenly, that beholde and take hede therof; and therfore he

4200-655: The vessel's helicopters crashed on a routine flight to the Antarctic Neumayer II base. The German pilot and a Dutch researcher were killed, and three other passengers were injured. On 17 October 2008, Polarstern was the first research ship ever to travel through both the Northeast Passage and the Northwest Passage in one cruise, thus circumnavigating the North Pole. The German government in 2015 issued

4270-412: Was 89.35 degrees North; (at epoch J2000 it was 89.26 degrees N). So it appears due north in the sky to a precision better than one degree, and the angle it makes with respect to the true horizon (after correcting for refraction and other factors) is within a degree of the latitude of the observer. The celestial pole will be nearest Polaris in 2100. Due to the precession of the equinoxes (as well as

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4340-439: Was about the same angular distance from β UMi as to α UMi by the end of late antiquity . The Greek navigator Pytheas in ca. 320 BC described the celestial pole as devoid of stars. However, as one of the brighter stars close to the celestial pole, Polaris was used for navigation at least from late antiquity, and described as ἀεί φανής ( aei phanēs ) "always visible" by Stobaeus (5th century), also termed Λύχνος ( Lychnos ) akin to

4410-433: Was as close to the pole as Polaris is now. In classical antiquity , Beta Ursae Minoris (Kochab) was closer to the celestial north pole than Alpha Ursae Minoris. While there was no naked-eye star close to the pole, the midpoint between Alpha and Beta Ursae Minoris was reasonably close to the pole, and it appears that the entire constellation of Ursa Minor , in antiquity known as Cynosura (Greek Κυνόσουρα "dog's tail"),

4480-430: Was configured to routinely process stars in the magnitude range 3 – 20. Beyond that limit, special procedures are used to download raw scanning data for the remaining 230 stars brighter than magnitude 3; methods to reduce and analyse these data are being developed; and it is expected that there will be "complete sky coverage at the bright end" with standard errors of "a few dozen μas". Gaia Data Release 2 does not include

4550-434: Was examined again with more advanced error correction and statistical techniques. Despite the advantages of Hipparcos astrometry , the uncertainty in its Polaris data has been pointed out and some researchers have questioned the accuracy of Hipparcos when measuring binary Cepheids like Polaris. The Hipparcos reduction specifically for Polaris has been re-examined and reaffirmed but there is still not widespread agreement about

4620-467: Was no constant northern star. Despite its relative brightness, it is not, as is popularly believed, the brightest star in the sky. Polaris was referenced in Nathaniel Bowditch 's 1802 book, American Practical Navigator , where it is listed as one of the navigational stars . The modern name Polaris is shortened from Neo-Latin stella polaris " polar star ", coined in the Renaissance when

4690-496: Was only 8 degrees from the south pole. In the next 7500 years, the south celestial pole will pass close to the stars Gamma Chamaeleontis (4200 AD), I Carinae , Omega Carinae (5800 AD), Upsilon Carinae , Iota Carinae (Aspidiske, 8100 AD) and Delta Velorum (Alsephina, 9200 AD). From the eightieth to the ninetieth centuries, the south celestial pole will travel through the False Cross . Around 14,000 AD Canopus will have

4760-420: Was reported by W. W. Campbell in 1899, which suggested this star is a binary system. Since Polaris A is a known cepheid variable, J. H. Moore in 1927 demonstrated that the changes in velocity along the line of sight were due to a combination of the four-day pulsation period combined with a much longer orbital period and a large eccentricity of around 0.6. Moore published preliminary orbital elements of

4830-449: Was several degrees away from the celestial pole; Gemma Frisius in the year 1547 determined this distance as 3°8'. An explicit identification of Mary as stella maris with the North Star ( Polaris ) becomes evident in the title Cynosura seu Mariana Stella Polaris (i.e. "Cynosure, or the Marian Polar Star"), a collection of Marian poetry published by Nicolaus Lucensis (Niccolo Barsotti de Lucca) in 1655. In 2022 Polaris' mean declination

4900-471: Was used as indicating the northern direction for the purposes of navigation by the Phoenicians . The ancient name of Ursa Minor, anglicized as cynosure , has since itself become a term for "guiding principle" after the constellation's use in navigation. Alpha Ursae Minoris (Polaris) was described as ἀειφανής (transliterated as aeiphanes ) meaning "always above the horizon", "ever-shining" by Stobaeus in

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