View source for Astronomy:Asterope (star)

[[File:M45map.jpg|thumb|Position of the Asterope pair in the Pleiades]]
'''Asterope''' or '''Sterope''' is the traditional name of a [[Astronomy:Double star|double star]], whose components are designated '''21 Tauri''' and '''22 Tauri''', in the [[Astronomy:Constellation|constellation]] of [[Astronomy:Taurus (constellation)|Taurus]],<ref>{{cite book | last = Burnham| first = Robert|  coauthors = | title = Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System| publisher = Courier Corporation| series = | volume = 3| edition = | date = 1978| location = | pages = 1883| language = | url = https://books.google.com/books?id=tBQoCSRdLAAC&pg=PA1883| doi = | id = | isbn = | mr = | zbl = | jfm = }}</ref> although the [[Organization:International Astronomical Union|International Astronomical Union]] now regards the name ''Asterope'' as only applying to 21 Tauri.<ref name="IAU-LSN">{{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars |publisher=IAU.org |accessdate=18 June 2018}}</ref> They are sometimes known as '''Sterope I''' and '''Sterope II'''.<ref name="Allen1899">{{Cite book
  | first=Richard Hinckley | last=Allen | year=1963
  | page=407 | title=Star names - Their Lore and Meaning
  | publisher=Dover Books
  | url=http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/home.html
  | accessdate=2016-09-14 }}</ref>

They are separated by 0.047° on the sky and are both members of the [[Astronomy:Pleiades|Pleiades]] [[Astronomy:Open cluster|open star cluster]] ([[Astronomy:Messier object|M45]]) and approximately 440 [[Astronomy:Light-year|light-year]]s from the [[Astronomy:Sun|Sun]].

==Nomenclature==
{{Starbox short |
 name=21 Tauri |
 epoch=[[Astronomy:J2000.0|J2000.0]] |
 constell=[[Astronomy:Taurus (constellation)|Taurus]] |
 ra=03<sup>h</sup> 45<sup>m</sup> 54.4<sup>s</sup> |
 dec=+24° 33' 17" |
 spectral=B8V |
 appmag_v=+5.76 |
 dist_ly=440 |
 dist_pc=135 |
 names=Asterope, Sterope I,<br />[[Astronomy:Star catalogue#BS, BSC, HR|HR]]&nbsp;1151, HD&nbsp;23432,<br />[[Astronomy:Star catalogue#BD/CD/CPD|BD]]+24&nbsp;553, HIP&nbsp;17579,<br />[[Astronomy:Star catalogue#SAO|SAO]]&nbsp;76159, GC&nbsp;4502
}}
{{Starbox short |
 name=22 Tauri |
 epoch=[[Astronomy:J2000.0|J2000.0]] |
 constell=[[Astronomy:Taurus (constellation)|Taurus]] |
 ra=03<sup>h</sup> 46<sup>m</sup> 02.9<sup>s</sup> |
 dec=+24° 31' 41" |
 spectral=A0Vn |
 appmag_v=+6.43 |
 dist_ly=440 |
 dist_pc=135 |
 names=Sterope II, [[Astronomy:Star catalogue#BS, BSC, HR|HR]]&nbsp;1152,<br />HD&nbsp;23441, [[Astronomy:Star catalogue#BD/CD/CPD|BD]]+24&nbsp;556,<br />HIP&nbsp;17588, [[Astronomy:Star catalogue#SAO|SAO]]&nbsp;76164,<br />GC&nbsp;4506
}}
''21 Tauri'' and ''22 Tauri'' are the stars' [[Astronomy:Flamsteed designation|Flamsteed designation]]s.

Asterope was one of the [[Astronomy:Pleiades (Greek mythology)|Pleiades sisters]] in [[Religion:Greek mythology|Greek mythology]].

In 2016, the [[Organization:International Astronomical Union|International Astronomical Union]] organized a [[Astronomy:IAU Working Group on Star Names|Working Group on Star Names]] (WGSN)<ref name="WGSN">{{citation
 | url=https://www.iau.org/science/scientific_bodies/working_groups/280/
 | title=IAU Working Group on Star Names (WGSN)
 | publisher=[[Organization:International Astronomical Union|International Astronomical Union]]
 | accessdate=22 May 2016 | postscript=. }}</ref> to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.<ref name="TriRpt18">{{cite web | url=https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf | page=5 | title=WG Triennial Report (2015-2018) - Star Names |accessdate=2018-07-14}}</ref> It approved the name ''Asterope'' for ''21 Tauri'' on 21 August 2016 and it is now so included in the List of IAU-approved Star Names.<ref name="IAU-LSN"/>

===Namesake===
USS Sterope (AK-96) was a United States Navy Crater class cargo ship named after the star.

==Properties==
21 Tauri is a blue-white [[Astronomy:Stellar classification|B-type]] [[Astronomy:Main sequence|main sequence dwarf]] with an [[Astronomy:Apparent magnitude|apparent magnitude]] of +5.76.

22 Tauri is a white [[Astronomy:Stellar classification|A-type]] [[Astronomy:Main sequence|main sequence dwarf]] with an [[Astronomy:Apparent magnitude|apparent magnitude]] of +6.43.

==References==
{{reflist}}

{{Stars of Taurus}}

[[Category:Taurus (constellation)]]
[[Category:B-type main-sequence stars]]
[[Category:A-type main-sequence stars]]
[[Category:Flamsteed objects|Tauri, 021 2]]
[[Category:Pleiades Open Cluster]]
[[Category:Stars with proper names]]
[[Category:Hipparcos objects|017579 88]]
[[Category:HR objects|1151 2]]
[[Category:Henry Draper Catalogue objects|023432 41]]
[[Category:Durchmusterung objects]]



{{Sourceattribution|Asterope (star)|1}}