It is a member of the Hyadesopen cluster. As such its age is well constrained at 625 million years.[5] It is claimed to be the heaviest among planet-harboring stars with reliable initial masses[5] although the star HD 13189 is potentially more massive.[8] Given its large mass, this star, though presently of spectral type K0 III, was formerly of spectral type A that has now evolved off the main sequence into the giant phase. It is regarded as a red clump giant; that is, a core-helium burning star.[5]
Since Epsilon Tauri lies near the plane of the ecliptic, it is sometimes occulted by the Moon and (very rarely) by planets.
It has an 11th magnitude companion 182 arcseconds from the primary.
ε Tauri (Latinised to Epsilon Tauri) is the star's Bayer designation; it also bears the Flamsteed designation of 74 Tauri. On discovery, the planet was designated Epsilon Tauri b (or Ain b).
The star bore the traditional name Ain (Arabicعين for "eye") and was given the name Oculus Boreus (Latin for "Northern eye") by John Flamsteed.[9][6] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[10] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[11] included a table of the first two batches of names approved by the WGSN; which included Ain for this star.
In July 2014, the International Astronomical Union launched NameExoWorlds, a process for giving proper names to certain exoplanets.[12] The process involved public nomination and voting for the new names.[13] In December 2015, the IAU announced the winning name was Amateru for this planet.[14]
The winning name was based on that submitted by the Kamagari Astronomical Observatory of Kure, Hiroshima Prefecture, Japan: namely 'Amaterasu', the Shinto goddess of the Sun, born from the left eye of the god Izanagi. The IAU substituted 'Amateru' – which is a common Japanese appellation for shrines when they enshrine Amaterasu – because 'Amaterasu' is already used for an asteroid (10385 Amaterasu).[15]
In 2007, a massive extrasolar planet was reported orbiting the star with a period of 1.6 years in a somewhat eccentric orbit. Its discoverers claimed it was the first planet ever discovered in an open cluster.[5]
^ abcdef"Entry for star HIP 20889". Vizier Catalogue Service. Retrieved 2015-09-13.
^ abcdefg"Notes for planet eps Tau b". The Extrasolar Planets Encyclopaedia. Retrieved 2015-09-13.
^ abBöhm-Vitense, Erika; et al. (December 2000), "Ultraviolet Emission Lines in BA and Non-BA Giants", The Astrophysical Journal, 545 (2): 992–999, Bibcode:2000ApJ...545..992B, doi:10.1086/317850.
^Gerard T. van Belle and Kaspar von Braun (2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal. 694 (2): 1085–1098. arXiv:0901.1206. Bibcode:2009ApJ...694.1085V. doi:10.1088/0004-637X/694/2/1085. S2CID 18370219.(web Preprint)
^ abcdefSato, Bun'ei; et al. (2007). "A Planetary Companion to the Hyades Giant ε Tauri". The Astrophysical Journal. 661 (1): 527–531. Bibcode:2007ApJ...661..527S. doi:10.1086/513503.
^ abAllen, Richard Hickley (1963). Star Names – Their Lore and Meaning. Dover Books. p. 391.
^"IAU Catalog of Star Names". Retrieved 28 July 2016.
^"Notes for planet HD 13189 b". The Extrasolar Planets Encyclopaedia. Retrieved 2015-09-15.
^Flamsteed, John (1725). Historia Coelestis Britannica. H. Meere. p. 47.
^"IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
^"Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Retrieved 28 July 2016.
^NameExoWorlds: An IAU Worldwide Contest to Name Exoplanets and their Host Stars. IAU.org. 9 July 2014
^. Archived from the original on 2015-08-15. Retrieved 2015-09-05.
^Final Results of NameExoWorlds Public Vote Released, International Astronomical Union, 15 December 2015.
^. Archived from the original on 2018-02-01. Retrieved 2015-12-21.
^(in Chinese)中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN978-986-7332-25-7.
^(in Chinese) 香港太空館 – 研究資源 – 亮星中英對照表 2008-10-25 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
epsilon, tauri, tauri, formally, named, orange, giant, star, located, approximately, parsecs, light, years, from, constellation, taurus, extrasolar, planet, designated, later, named, amateru, believed, orbiting, star, location, tauri, circled, observation, dat. Epsilon Tauri or e Tauri formally named Ain ˈ eɪ n 7 is an orange giant star located approximately 45 parsecs 147 light years from the Sun in the constellation of Taurus 2 An extrasolar planet designated Epsilon Tauri b later named Amateru is believed to be orbiting the star Epsilon TauriLocation of e Tauri circled Observation dataEpoch J2000 Equinox J2000Constellation TaurusRight ascension 04h 28m 37 00s 1 Declination 19 10 50 1 Apparent magnitude V 3 53 2 CharacteristicsSpectral type K0III 2 B V color index 1 014 1 AstrometryProper motion m RA 106 19 0 38 1 mas yr Dec 37 84 0 30 1 mas yrParallax p 22 24 0 25 mas 1 Distance147 2 ly 45 0 0 5 pc Absolute magnitude MV 0 145 3 DetailsMass2 7 0 1 2 M Radius12 692 0 545 4 R Luminosity97 8 5 L Temperature4901 20 2 KMetallicity Fe H 0 17 0 04 2 dexRotational velocity v sin i 3 0 3 km sAge625 2 MyrOther designationsAin Oculus Boreus 6 Epsilon Tau e Tau 74 Tau BD 18 640 FK5 164 GC 5430 HD 28305 HIP 20889 HR 1409 SAO 93954 CCDM J04286 1911Database referencesSIMBADdataIt is a member of the Hyades open cluster As such its age is well constrained at 625 million years 5 It is claimed to be the heaviest among planet harboring stars with reliable initial masses 5 although the star HD 13189 is potentially more massive 8 Given its large mass this star though presently of spectral type K0 III was formerly of spectral type A that has now evolved off the main sequence into the giant phase It is regarded as a red clump giant that is a core helium burning star 5 Since Epsilon Tauri lies near the plane of the ecliptic it is sometimes occulted by the Moon and very rarely by planets It has an 11th magnitude companion 182 arcseconds from the primary Contents 1 Nomenclature 2 Planetary system 3 See also 4 References 5 External linksNomenclature Edite Tauri Latinised to Epsilon Tauri is the star s Bayer designation it also bears the Flamsteed designation of 74 Tauri On discovery the planet was designated Epsilon Tauri b or Ain b The star bore the traditional name Ain Arabic عين for eye and was given the name Oculus Boreus Latin for Northern eye by John Flamsteed 9 6 In 2016 the International Astronomical Union organized a Working Group on Star Names WGSN 10 to catalog and standardize proper names for stars The WGSN s first bulletin of July 2016 11 included a table of the first two batches of names approved by the WGSN which included Ain for this star In July 2014 the International Astronomical Union launched NameExoWorlds a process for giving proper names to certain exoplanets 12 The process involved public nomination and voting for the new names 13 In December 2015 the IAU announced the winning name was Amateru for this planet 14 The winning name was based on that submitted by the Kamagari Astronomical Observatory of Kure Hiroshima Prefecture Japan namely Amaterasu the Shinto goddess of the Sun born from the left eye of the god Izanagi The IAU substituted Amateru which is a common Japanese appellation for shrines when they enshrine Amaterasu because Amaterasu is already used for an asteroid 10385 Amaterasu 15 In Chinese 畢宿 Bi Xiu meaning Net refers to an asterism consisting e Tauri d3 Tauri d1 Tauri g Tauri Aldebaran 82 Tauri 71 Tauri and l Tauri 16 Consequently the Chinese name for e Tauri itself is 畢宿一 Bi Xiu yi the First Star of Net 17 Planetary system EditIn 2007 a massive extrasolar planet was reported orbiting the star with a period of 1 6 years in a somewhat eccentric orbit Its discoverers claimed it was the first planet ever discovered in an open cluster 5 The Epsilon Tauri planetary system 5 Companion in order from star Mass Semimajor axis AU Orbital period days Eccentricity Inclination Radiusb Amateru gt 7 6 0 2 MJ 1 93 0 03 594 9 5 3 0 151 0 023 See also EditEpsilon Tauri in fictionReferences Edit a b c d e f Entry for star HIP 20889 Vizier Catalogue Service Retrieved 2015 09 13 a b c d e f g Notes for planet eps Tau b The Extrasolar Planets Encyclopaedia Retrieved 2015 09 13 a b Bohm Vitense Erika et al December 2000 Ultraviolet Emission Lines in BA and Non BA Giants The Astrophysical Journal 545 2 992 999 Bibcode 2000ApJ 545 992B doi 10 1086 317850 Gerard T van Belle and Kaspar von Braun 2009 Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars The Astrophysical Journal 694 2 1085 1098 arXiv 0901 1206 Bibcode 2009ApJ 694 1085V doi 10 1088 0004 637X 694 2 1085 S2CID 18370219 web Preprint a b c d e f Sato Bun ei et al 2007 A Planetary Companion to the Hyades Giant e Tauri The Astrophysical Journal 661 1 527 531 Bibcode 2007ApJ 661 527S doi 10 1086 513503 a b Allen Richard Hickley 1963 Star Names Their Lore and Meaning Dover Books p 391 IAU Catalog of Star Names Retrieved 28 July 2016 Notes for planet HD 13189 b The Extrasolar Planets Encyclopaedia Retrieved 2015 09 15 Flamsteed John 1725 Historia Coelestis Britannica H Meere p 47 IAU Working Group on Star Names WGSN Retrieved 22 May 2016 Bulletin of the IAU Working Group on Star Names No 1 PDF Retrieved 28 July 2016 NameExoWorlds An IAU Worldwide Contest to Name Exoplanets and their Host Stars IAU org 9 July 2014 NameExoWorlds The Process Archived from the original on 2015 08 15 Retrieved 2015 09 05 Final Results of NameExoWorlds Public Vote Released International Astronomical Union 15 December 2015 NameExoWorlds The Approved Names Archived from the original on 2018 02 01 Retrieved 2015 12 21 in Chinese 中國星座神話 written by 陳久金 Published by 台灣書房出版有限公司 2005 ISBN 978 986 7332 25 7 in Chinese 香港太空館 研究資源 亮星中英對照表 Archived 2008 10 25 at the Wayback Machine Hong Kong Space Museum Accessed on line November 23 2010 External links Edit Star Names Frosty Drew Observatory Retrieved 2008 06 24 eps Tau SIMBAD Centre de donnees astronomiques de Strasbourg Retrieved from https en wikipedia org w index php title Epsilon Tauri amp oldid 1143915323, wikipedia, wiki, book, books, library,
