Polaris - wikipedia Polaris `` North Star '' redirects here. For other uses, see North Star ( disambiguation ) and Polaris ( disambiguation ). Polaris Chart showing location of Polaris ( α Ursae Minoris ) near the North Celestial Pole. Observation data Epoch J2000 Equinox Constellation Ursa Minor α UMi Aa Right ascension 02 31 49.09 Declination + 89 ° 15 ′ 50.8 '' Apparent magnitude ( V ) 1.98 α UMi Ab Right ascension Declination Apparent magnitude ( V ) 9.2 α UMi B Right ascension 02 30 41.63 Declination + 89 ° 15 ′ 38.1 '' Apparent magnitude ( V ) 8.7 Characteristics α UMi Aa Spectral type F7Ib U − B color index 0.38 B − V color index 0.60 Variable type Classical Cepheid α UMi Ab Spectral type F6V α UMi B Spectral type F3V U − B color index 0.01 B − V color index 0.42 Astrometry Radial velocity ( R ) − 17 km / s Proper motion ( μ ) RA : 44.48 ± 0.11 mas / yr Dec. : − 11.85 ± 0.13 mas / yr Parallax ( π ) 7.54 ± 0.11 mas Distance 323 -- 433 ly ( 99 -- 133 pc ) Absolute magnitude ( M ) − 3.6 ( α UMi Aa ) 3.6 ( α UMi Ab ) 3.1 ( α UMi B ) Orbit Primary α UMi Aa Companion α UMi Ab Period ( P ) 29.59 yr Semi-major axis ( a ) 0.133 '' Eccentricity ( e ) 0.608 Inclination ( i ) 128 ° Longitude of the node ( Ω ) 19 ° Argument of periastron ( ω ) ( secondary ) 303 ° Semi-amplitude ( K ) ( primary ) 3.72 km / s Details α UMi Aa Mass 5.4 M Radius 37.5 R Luminosity ( bolometric ) 1,260 L Surface gravity ( log g ) 2.2 cgs Temperature 6015 K Metallicity 112 % solar Rotation 119 days Rotational velocity ( v sin i ) 14 km / s Age 7 × 10 years α UMi Ab Mass 1.26 M Radius 1.04 R Luminosity ( bolometric ) Age 7 × 10 years α UMi B Mass 1.39 M Radius 1.38 R Luminosity ( bolometric ) 3.9 L Surface gravity ( log g ) 4.3 cgs Temperature 6900 K Rotational velocity ( v sin i ) 110 km / s Age 7 × 10 years Position ( relative to α UMi Aa ) Component α UMi Ab Epoch of observation 2005.5880 Angular distance 0.172 '' Position angle 231.4 ° Position ( relative to α UMi Aa ) Component α UMi B Epoch of observation 2005.5880 Angular distance 18.217 '' Position angle 230.540 ° Other designations Polaris, North Star, 1 Ursae Minoris, HR 424, BD + 88 ° 8, HD 8890, SAO 308, FK5 907, GC 2243, ADS 1477, CCDM J02319 + 8915, HIP 11767, Cynosura, Alruccabah, Phoenice, Navigatoria, Star of Arcady, Yilduz, Mismar Database references SIMBAD α UMi A α UMi B Polaris, designated Alpha Ursae Minoris ( α Ursae Minoris, abbreviated Alpha UMi, α UMi ), commonly the North Star or Pole Star, is the brightest star in the constellation of Ursa Minor. It is very close to the north celestial pole, making it the current northern pole star. The revised Hipparcos parallax gives a distance to Polaris of about 433 light - years ( 133 parsecs ), while calculations by other methods derive distances around 30 % closer. Polaris is a multiple star, comprising the main star ( Polaris Aa, a yellow supergiant ) in orbit with a smaller companion ( Polaris Ab ) ; the pair in orbit with Polaris B ( discovered in August 1779 by William Herschel ). There were once thought to be two more distant components -- Polaris C and Polaris D -- but these have been shown not to be physically associated with the Polaris system. Contents 1 Stellar system 2 Variable star 3 Names 4 Role as pole star 5 Distance 6 History of observations 7 See also 8 References 9 External links Stellar system Polaris components as seen by the Hubble Space Telescope Polaris Aa is a 5.4 solar mass ( M ) F7 yellow supergiant of spectral type Ib. This 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 2400 astronomical units ( au ), and Polaris Ab ( or P ), a very close F6 main - sequence star with an 18.8 au radius orbit and 1.26 M. Polaris B can be seen even 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. By examining the spectrum of Polaris A, it was also discovered in 1929 that it was a very close binary, with the secondary being a dwarf ( variously α UMi P, α UMi an or α UMi Ab ), which had been theorized in earlier observations ( Moore, J.H. and Kholodovsky, E.A. ). In January 2006, NASA released images, from the Hubble telescope, that showed the three members of the Polaris ternary system. The nearest dwarf star is in an orbit of only 18.5 au ( 2.8 billion km ) from Polaris A, about the distance between the Sun and Uranus ), which explains why its light is swamped by its close and much brighter companion. Variable star Ursa Major and Ursa Minor in relation to Polaris Polaris A, the supergiant primary component, 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 during its pulsations 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 a hiatus in 1963 -- 1965. This was originally thought to be due to secular redward 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 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 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 ''. Names This artist 's concept shows : supergiant Polaris A, dwarf Polaris Ab, and the distant dwarf companion Polaris B. The modern name Polaris is shortened from New Latin stella polaris `` polar star '', coined in the Renaissance era, when 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 ° 7 ' from the celestial pole. 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 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 '', compared to the quality of steadfastness or honour. In the Hindu Puranas, it became personified under 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 Bartholomeus Anglicus, c. 1270s ) 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 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 Cyonsura as a name of the star, is 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. Its name in traditional pre-Islamic Arab astronomy was Al - Judeyy الجدي, and that name was used in medieval Islamic astronomy as well. In those times, it was not yet as close to 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 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 is only noticeable over centuries. In Inuit astronomy, Polaris is known as Niqirtsuituq. It is depicted on the flag and coat of arms of the Canadian Inuit territory of Nunavut, as well as on the flag of the U.S. state of Alaska. Role as pole star Main article : Pole star A typical Northern Hemisphere star trail with Polaris in the center Because Polaris lies nearly in a direct line with the axis of the Earth 's rotation `` 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 moving of Polaris towards and, in 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. Historically, the celestial pole was close to Thuban around 2750 BC, and during classical antiquity it was closer to Kochab ( β UMi ) than to Polaris. It 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 ), and it could reasonably be described as stella polaris from about the High Middle Ages. In more recent history, 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 was no constant northern star. It was referenced in Nathaniel Bowditch 's 1802 book, American Practical Navigator, where it is listed as one of the navigational stars. At present, Polaris is 0.75 ° away from the pole of rotation ( 1.4 times the Moon disc ) and hence revolves around the pole in a small circle 1.5 ° in diameter. Only twice during every sidereal day does Polaris accurately define the true north azimuth ; the rest of the time, it is slightly displaced eastward or westward, and the bearing must be corrected using tables or a rough rule of thumb. The best approximate was made using the leading edge of the `` Big Dipper '' asterism in the constellation Ursa Major as a point of reference. The leading edge ( defined by the stars Dubhe and Merak ) was referenced to a clock face, and the true azimuth of Polaris worked out for different latitudes. Distance Stellar parallax is the basis for the parsec, which is the distance from the Sun to an astronomical object which has a parallax angle of one arcsecond. ( 1 au and 1 pc are not to scale, 1 pc = about 206265 au ) Many recent papers calculate the distance to Polaris at about 433 light - years ( 133 parsecs ), in agreement with parallax measurements from the Hipparcos astrometry satellite. Older distance estimates were often slightly less, and recent research based on high resolution spectral analysis suggests it may be up to 100 light years closer ( 323 ly / 99 pc ). Polaris 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. Selected distance estimates to Polaris Year Distance, ly ( pc ) Notes 433 ly ( 133 pc ) Hipparcos 2006 330 ly ( 101 pc ) Turner 2008 359 ly ( 110 pc ) Usenko & Klochkova 2013 323 ly ( 99 pc ) Turner, et al. 2014 > = 385 ly ( > = 118 pc ) Neilson 2015 346 ly ( 106 pc ) Fadeyev 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 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 researches 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 the distance. The next major step in high precision parallax measurements will come from Gaia, a space astrometry mission launched in 2013 and intended to measure stellar parallax to within 25 microarcseconds ( μas ). It was expected that Gaia would not be able to take measurements on bright stars like Polaris, but it may help with measurements of other members of assumed associations and with the general galactic distance scale. Radio telescopes have also been used to produce accurate parallax measurements at large distances, but these require a compact radio source in close association with the star which is typically only the case for cool supergiants with masers in their circumstellar material. Gaia was launched in 2013 and began its mission to record data 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 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 ''. Determining an accurate distance to Polaris is important for the cosmic distance ladder because, until new data comes, it is the only Cepheid variable for which precision distance data exists, which has a ripple effect on distance measurements that use this `` ruler ''. History of observations Polaris in stellar catalogues and atlases Source Presence Ptolemy ( ~ 169 ) Yes Al - Sufi ( 964 ) Yes Al - Biruni ( ~ 1030 ) Yes Khayyam ( ~ 1100 ) Yes Al - Tusi ( 1272 ) No Ulugh Beg ( 1437 ) Yes Copernicus ( 1543 ) Yes Schöner ( 1551 ) Yes Brahe ( 1598 ) Yes Brahe ( 1602 ) Yes Source Presence Bayer ( 1603 ) Yes De Houtman ( 1603 ) No Kepler ( 1627 ) Yes Schiller ( 1627 ) Yes Halley ( 1679 ) No Hevelius ( 1690 ) Yes Flamsteed ( 1725 ) Yes Flamsteed ( 1729 ) Yes Bode ( 1801a ) Yes Bode ( 1801b ) Yes See also Polar alignment Polaris in fiction References ^ Jump up to : Evans, N.R. ; Schaefer, G.H. ; Bond, H.E. ; Bono, G. ; Karovska, M. ; Nelan, E. ; Sasselov, D. ; Mason, B.D. ( 2008 ). `` Direct Detection of the Close Companion of Polaris with The Hubble Space Telescope ''. The Astronomical Journal. 136 ( 3 ) : 1137. arXiv : 0806.4904. Bibcode : 2008AJ... 136.1137 E. doi : 10.1088 / 0004 - 6256 / 136 / 3 / 1137. ^ Jump up to : Lee, B.C. ; Mkrtichian, D.E. ; Han, I. ; Park, M.G. ; Kim, K.M. ( 2008 ). `` Precise Radial Velocities of Polaris : Detection of Amplitude Growth ''. The Astronomical Journal. 135 ( 6 ) : 2240. arXiv : 0804.2793. Bibcode : 2008AJ... 135.2240 L. doi : 10.1088 / 0004 - 6256 / 135 / 6 / 2240. ^ Jump up to : Samus, N.N. ; Durlevich, O.V. ; et al. ( 2009 ). `` VizieR Online Data Catalog : General Catalogue of Variable Stars ( Samus+ 2007 -- 2013 ) ''. VizieR On - line Data Catalog : B / gcvs. Originally published in : 2009yCat... 102025S. 1 : 02025. Bibcode : 2009yCat... 102025S. ^ Jump up to : Usenko, I.A. ; Klochkova, V.G. ( 2008 ). `` Polaris B, an optical companion of the Polaris ( α UMi ) system : Atmospheric parameters, chemical composition, distance and mass ''. Monthly Notices of the Royal Astronomical Society : Letters. 387 : L1. arXiv : 0708.0333. Bibcode : 2008MNRAS. 387L... 1U. doi : 10.1111 / j. 1745 - 3933.2008. 00426. x. ^ Jump up to : Van Leeuwen, F. ( 2007 ). `` Validation of the new Hipparcos reduction ''. Astronomy and Astrophysics. 474 ( 2 ) : 653 -- 664. arXiv : 0708.1752. Bibcode : 2007A&A... 474... 653V. doi : 10.1051 / 0004 - 6361 : 20078357. ^ Jump up to : Turner, D.G. ; Kovtyukh, V.V. ; Usenko, I.A. ; Gorlova, N.I. ( 2013 ). `` The Pulsation Mode of the Cepheid Polaris ''. The Astrophysical Journal Letters. 762 : L8. arXiv : 1211.6103. Bibcode : 2013ApJ... 762L... 8T. doi : 10.1088 / 2041 - 8205 / 762 / 1 / L8. ^ Jump up to : Fadeyev, Y.A. ( 2015 ). `` Evolutionary status of Polaris ''. Monthly Notices of the Royal Astronomical Society. 449 : 1011. arXiv : 1502.06463. Bibcode : 2015MNRAS. 449.1011 F. doi : 10.1093 / mnras / stv412. ^ Jump up to : Usenko, I.A. ; Miroshnichenko, A.S. ; Klochkova, V.G. ; Yushkin, M.V. ( 2005 ). `` Polaris, the nearest Cepheid in the Galaxy : Atmosphere parameters, reddening and chemical composition ''. Monthly Notices of the Royal Astronomical Society. 362 ( 4 ) : 1219. Bibcode : 2005MNRAS. 362.1219 U. doi : 10.1111 / j. 1365 - 2966.2005. 09353. x. Jump up ^ Cayrel de Strobel, G. ; Soubiran, C. ; Ralite, N. ( 2001 ). `` Catalogue of ( Fe / H ) determinations for FGK stars : 2001 edition ''. Astronomy and Astrophysics. 373 : 159. arXiv : astro - ph / 0106438. Bibcode : 2001A&A... 373... 159C. doi : 10.1051 / 0004 - 6361 : 20010525. ^ Jump up to : Wielen, R. ; Jahreiß, H. ; Dettbarn, C. ; Lenhardt, H. ; Schwan, H. ( 2000 ). `` Polaris : Astrometric orbit, position, and proper motion ''. Astronomy and Astrophysics. 360 : 399. arXiv : astro - ph / 0002406. Bibcode : 2000A&A... 360... 399W. Jump up ^ Evans, Nancy Remage ; Guinan, Edward ; Engle, Scott ; Wolk, Scott J. ; Schlegel, Eric ; Mason, Brian D. ; Karovska, Margarita ; Spitzbart, Bradley ( 2010 ). `` Chandra Observation of Polaris : Census of Low - mass Companions ''. The Astronomical Journal. 139 ( 5 ) : 1968. Bibcode : 2010AJ... 139.1968 E. doi : 10.1088 / 0004 - 6256 / 139 / 5 / 1968. Jump up ^ `` There 's More to the North Star Than Meets the Eye ''. Hubblesite.org. 2006 - 01 - 09. Retrieved 2012 - 04 - 14. ^ Jump up to : Evans, N.R. ; Sasselov, D.D. ; Short, C.I. ( 2002 ). `` Polaris : Amplitude, Period Change, and Companions ''. The Astrophysical Journal. 567 ( 2 ) : 1121. Bibcode : 2002ApJ... 567.1121 E. doi : 10.1086 / 338583. Jump up ^ Hertzsprung, Ejnar ( August 1911 ). `` Nachweis der Veränderlichkeit von α Ursae Minoris ''. Astronomische Nachrichten ( in German ). 189 ( 6 ) : 89. Bibcode : 1911AN... 189... 89H. doi : 10.1002 / asna. 19111890602. ^ Jump up to : Turner, D.G. ; Savoy, J. ; Derrah, J. ; Abdel ‐ Sabour Abdel ‐ Latif, M. ; Berdnikov, L.N. ( 2005 ). `` The Period Changes of Polaris ''. Publications of the Astronomical Society of the Pacific. 117 ( 828 ) : 207. Bibcode : 2005PASP... 117... 207T. doi : 10.1086 / 427838. ^ Jump up to : Neilson, H.R. ; Engle, S.G. ; Guinan, E. ; Langer, N. ; Wasatonic, R.P. ; Williams, D.B. ( 2012 ). `` The Period Change of the Cepheid Polaris Suggests Enhanced Mass Loss ''. The Astrophysical Journal. 745 ( 2 ) : L32. arXiv : 1201.0761. Bibcode : 2012ApJ... 745L... 32N. doi : 10.1088 / 2041 - 8205 / 745 / 2 / L32. Jump up ^ Irion, R ( 2004 ). `` American Astronomical Society meeting. As inconstant as the Northern Star ''. Science. 304 ( 5678 ) : 1740 -- 1. doi : 10.1126 / science. 304.5678. 1740b. PMID 15205508. Jump up ^ IAU Working Group on Star Names `` IAU Catalog of Star Names ''. Retrieved 28 July 2016. Jump up ^ Gemmae Frisii de astrolabo catholico liber : quo latissime patentis instrumenti multiplex usus explicatur, & quicquid uspiam rerum mathematicarum tradi possit continetur, Steelsius ( 1556 ), p. 20 ; see also Kunitzsch, Paul ; Smart, Tim ( 2006 ). A Dictionary of Modern star Names : A Short Guide to 254 Star Names and Their Derivations ( 2nd rev. ed. ). Cambridge, Massachusetts : Sky Publishing. p. 23. ISBN 978 - 1 - 931559 - 44 - 7. Jump up ^ Bruce Dickins, Runic and heroic poems of the old Teutonic peoples ( 1915 ), p. 18 ; Dickins ' `` a circumpolar constellation '' is attributed to L. Botkine, La Chanson des Runes ( 1879 ). Jump up ^ J.O. Halliwell, ( ed. ), The Works of William Shakespeare vol. 5 ( 1856 ), p. 40. ) Jump up ^ Al - Sufi, AbdulRahman ( 964 ). `` Book Of Fixed Stars ''. Jump up ^ Schjellerup, Hans ( 1874 ). `` Description des Etoiles fixes ''. p. 45. ^ Jump up to : Ridpath, Ian, ed. ( 2004 ). Norton 's Star Atlas. New York : Pearson Education. p. 5. ISBN 0 - 13 - 145164 - 2. Around 4800 years ago Thuban ( α Draconis ) lay a mere 0 °. 1 from the pole. Deneb ( α Cygni ) will be the brightest star near the pole in about 8000 years ' time, at a distance of 7 °. 5. Jump up ^ `` Star Tales - Ursa Minor ''. Retrieved 20 August 2016. Jump up ^ Nathaniel Bowditch ; National Imagery and Mapping Agency ( 2002 ). `` 15 Navigational Astronomy ''. The American practical navigator : an epitome of navigation. Paradise Cay Publications. p. 248. ISBN 978 - 0 - 939837 - 54 - 0. Jump up ^ `` A visual method to correct a ship 's compass using Polaris using Ursa Major as a point of reference ''. Retrieved Aug 7, 2016. Jump up ^ Neilson, H.R. ( 2014 ). `` Revisiting the fundamental properties of the Cepheid Polaris using detailed stellar evolution models ''. Astronomy & Astrophysics. 563 : A48. arXiv : 1402.1177. Bibcode : 2014A&A... 563A... 48N. doi : 10.1051 / 0004 - 6361 / 201423482. Jump up ^ Van Leeuwen, F. ( 1997 ). `` The Hipparcos Mission ''. Space Science Reviews. 81 ( 3 / 4 ) : 201. Bibcode : 1997SSRv... 81... 201V. doi : 10.1023 / A : 1005081918325. Jump up ^ Van Leeuwen, F. ( 2013 ). `` The HIPPARCOS parallax for Polaris ''. Astronomy & Astrophysics. 550 : L3. arXiv : 1301.0890. Bibcode : 2013A&A... 550L... 3V. doi : 10.1051 / 0004 - 6361 / 201220871. Jump up ^ Liu, C. ; Bailer - Jones, C.A.L. ; Sordo, R. ; Vallenari, A. ; et al. ( 2012 ). `` The expected performance of stellar parametrization with Gaia spectrophotometry ''. Monthly Notices of the Royal Astronomical Society. 426 ( 3 ) : 2463. arXiv : 1207.6005. Bibcode : 2012MNRAS. 426.2463 L. doi : 10.1111 / j. 1365 - 2966.2012. 21797. x. Jump up ^ `` Radio Telescopes ' Precise Measurements Yield Rich Scientific Payoffs ''. Jump up ^ Martín - Fleitas, J. ; Mora, A. ; Sahlmann, J. ; Kohley, R. ; Massart, B. ; et al. ( 2 August 2014 ), Oschmann, Jacobus M. ; Clampin, Mark ; Fazio, Giovanni G. ; MacEwen, Howard A., eds., Enabling Gaia observations of naked - eye stars, Proc. SPIE, 9143, arXiv : 1408.3039 v1, doi : 10.1117 / 12.2056325 Jump up ^ T. Prusti ; et al. ( GAIA Collaboration ) ( 2016 ), `` The Gaia mission '' ( PDF ), Astronomy and Astrophysics ( forthcoming article ), doi : 10.1051 / 0004 - 6361 / 201629272, retrieved 21 September 2016 Jump up ^ ( 1 ) External links Wikimedia Commons has media related to Polaris. Info on Polaris Finding the Pole Star Polaris at Constellation Guide Preceded by Kochab & Pherkad Pole star 500 -- 3000 Succeeded by Gamma Cephei Coordinates : 02 31 48.7, + 89 ° 15 ′ 51 '' Stars of Ursa Minor Bayer α ( Polaris ) β ( Kochab ) γ ( Pherkad ) δ ( Yildun ) ε ζ ( Akhfa al Farkadain ) η ( Anwar al Farkadain ) θ λ π π Flamsteed 5 6 8 9 10 11 12 14 17 19 20 24 Variable U V Z RR RU RW SS UY VX HR 286 4683 4950 5073 5139 5184 5334 5479 5556 5629 5672 5691 5844 6034 6088 6173 6191 6238 6267 6529 HD 150706 Other Calvera H1504 + 65 WD 1337 + 705 WISE 1506 + 7027 List VIAF : 248278544 LCCN : sh85104178 GND : 4582527 - 0 BNF : cb124572759 ( data ) Retrieved from `` https://en.wikipedia.org/w/index.php?title=Polaris&oldid=813132991 '' Categories : Bayer objects Flamsteed objects Classical Cepheid variables F - type main - sequence stars F - type supergiants Henry Draper Catalogue objects Hipparcos objects HR objects Northern pole stars Stars with proper names Triple star systems Ursa Minor ( constellation ) Durchmusterung objects Hidden categories : CS1 German - language sources ( de ) Articles containing Ancient Greek - language text Wikipedia articles with VIAF identifiers Wikipedia articles with LCCN identifiers Wikipedia articles with GND identifiers Wikipedia articles with BNF identifiers Talk Contents About Wikipedia Afrikaans Asturianu Azərbaycanca Беларуская Беларуская ( тарашкевіца ) ‎ Български Brezhoneg Català Čeština Corsu Cymraeg Dansk Davvisámegiella Deutsch Eesti Ελληνικά Español Esperanto Euskara فارسی Français Galego 한국어 Hawaiʻi Հայերեն हिन्दी Hrvatski Bahasa Indonesia Ирон Íslenska Italiano עברית ქართული Kaszëbsczi Қазақша Коми Latina Latviešu Lëtzebuergesch Lietuvių Limburgs Magyar Македонски Malagasy മലയാളം मराठी Bahasa Melayu မြန်မာဘာသာ Nāhuatl Nederlands 日本 語 Norsk Norsk nynorsk Occitan Олык марий Oʻzbekcha / ўзбекча Piemontèis Polski Português Română Русский Саха тыла Scots Simple English Slovenčina Slovenščina Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska Татарча / tatarça Türkçe Українська اردو Vahcuengh Vèneto Tiếng Việt 文言 粵語 中文 Edit links This page was last edited on 1 December 2017, at 23 : 53. 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Question: what's the name of the north star
Answer: Polaris