Editing Beta Arietis

{{Short description|Binary star system in the constellation Aries}}
{{Starbox begin
| name=β Arietis
}}
{{Starbox image
| image=
{{Location mark
 | image=Aries constellation map.svg
 | alt= | float=center | width=240 | label= | position=right
 | mark=Red circle.svg | mark_width=12 | mark_link=β Arietis
 | x%=88.7 | y%=42.4
}}
|caption=Location of β Arietis (circled)
}}
{{Starbox observe
| epoch=J2000
| ra       = {{RA|01|54|38.41099}}<ref name=aaa474_2_653/>
| dec      = {{DEC|+20|48|28.9133}}<ref name=aaa474_2_653/>
| appmag_v = 2.655<ref name=sps1966/> (2.712 + 5.789<ref name=sb2/>)
| constell = [[Aries (constellation)|Aries]]
}}
{{Starbox character
| class    = A3V + G2V<ref name=sb2/>
| b-v      = +0.142<ref name=sps1966/>
| u-b      = +0.170<ref name=sps1966/>
| variable =
}}
{{Starbox astrometry
| radial_v    = −1.9{{±|0.9}}<ref name=gcsrv/>
| prop_mo_ra  = +98.74<ref name=aaa474_2_653/>
| prop_mo_dec = −110.41<ref name=aaa474_2_653/>
| parallax    = 55.827
| p_error     = 0.308
| parallax_footnote = <ref name=sb2/>
| absmag_v    = 1.382 (1.444 + 4.521)<ref name=sb2/>
}}
{{Starbox visbin
| name         = Beta Arietis B
| reference    = <ref name=apj356_641/>
| period_unitless = {{nowrap|106.9954 ± 0.0005 days}}
| axis_unitless = {{val|36.1|0.3|ul=mas}}
| eccentricity = 0.903{{±|0.012}}
| inclination  = 44.7{{±|1.3}}
| node         = 79.1{{±|0.8}}
| periarg      = 209.1{{±|1.2}}
}}
{{Starbox detail
| source      = <ref name=sb2/>
| component1  = A
| mass        = {{val|2.067|0.057}}
| radius      = {{Solar radius calculator|type=logLT|1=1.32|logLerr=0.1|2=8759|Terr=0|decimals=3}}{{Efn|name=rad}}
| luminosity  = {{val|20.9|5.4|4.3}}
| temperature = 8,759
| gravity     = 4.0<ref name=aaass27_35/>
| metal_fe    = 0.16<ref name=aaass27_35/>
| rotational_velocity = 73<ref name=aaa463_2_671/>
| age_myr     = {{val|447|261|165}}
| component2  = B
| mass2       = {{val|1.058|0.026}}
| radius2     = {{Solar radius calculator|type=logLT|1=0.11|logLerr=0.05|2=5811|Terr=0|decimals=3}}{{Efn|name=rad}}
| luminosity2 = {{val|1.29|0.16|0.14}}
| temperature2 = 5,811
}}
{{Starbox catalog
| names = {{odlist | name=Sheratan, Sharatan, Al Sharatain<ref name=allen1899/> | F=6 Arietis | Gl=80 | HR=553 | BD=+20°306 | HD=11636 | SAO=75012 | FK5=66 | HIP=8903 }}<ref name=SIMBAD/>
}}
{{Starbox reference
| Simbad=HD+11636
| ARICNS = 00161
}}
{{Starbox end}}

'''Beta Arietis''' is a [[binary star]] system in the [[constellation]] of [[Aries (constellation)|Aries]], marking the ram's second horn. Its identifier is a [[Bayer designation]] that is [[Romanization of Greek|Latinized]] from β Arietis, and abbreviated '''Beta Ari''' or '''β Ari'''. It has the official name '''Sheratan''', pronounced {{IPAc-en|ˈ|ʃ|ɛr|ə|t|æ|n}}.<ref name=Kunitzsch/><ref name="IAU-CSN"/> This system is visible to the [[naked eye]] as a point of light with a combined [[apparent visual magnitude]] of 2.65, making this the second-brightest star in the constellation. Located at a distance of {{convert|58.4|ly|pc|abbr=out|lk=on}}, the pair orbit each other with a [[orbital period|period]] of 107&nbsp;days.

==Nomenclature==
''Beta Arietis'' is the star's [[Bayer designation]]. It also bears the [[Flamsteed designation]] ''6 Arietis''.

The traditional name, ''Sheratan'' (or ''Sharatan, Sheratim),''<ref name=allen1899/> in full ''Al Sharatan,'' is from the Arabic الشرطان ''aš-šaraţān'' "the two signs", a reference to the star having marked the northern vernal equinox together with [[Gamma Arietis]] several thousand years ago.{{Citation needed|date=December 2011}} In 2016, the [[International Astronomical Union]] organized a [[IAU Working Group on Star Names|Working Group on Star Names]] (WGSN)<ref name="WGSN"/> to catalogue and standardize proper names for stars. The WGSN approved the name ''Sheratan'' for this star on August 21, 2016 and it is now so entered in the IAU Catalog of Star Names.<ref name="IAU-CSN"/>

In [[Chinese astronomy|Chinese]], {{lang|zh|婁宿}} ({{lang|zh-Latn|Lóu Xiù}}), meaning ''[[Bond (Chinese constellation)|Bond]] (asterism)'', refers to an asterism consisting of β Arietis, [[Gamma Arietis|γ Arietis]] and [[Hamal|α Arietis]].<ref>{{in lang|zh}} ''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}}.</ref> Consequently, the [[Chinese star names|Chinese name]] for β Arietis itself is {{lang|zh|婁宿一}} ({{lang|zh-Latn|Lóu Su yī}}, {{langx|en|the First Star of Bond}}).<ref>{{in lang|zh}} [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_s.htm 香港太空館 - 研究資源 - 亮星中英對照表] {{webarchive|url=https://web.archive.org/web/20100818141141/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_s.htm |date=2010-08-18 }}, Hong Kong Space Museum. Accessed on line November 23, 2010.</ref>

==Properties==
Beta Arietis has an [[Apparent magnitude|apparent visual magnitude]] of 2.65. Based on dynamical [[parallax]] measurements, it is located at a distance of {{Convert|58.4|ly|pc|abbr=off|lk=on}} from Earth.<ref name=sb2/> This is a [[spectroscopic binary]] star system consisting of a pair of stars orbiting around each other with a separation that can not currently be resolved with a conventional telescope. However, the pair have been resolved using the [[Mark III Stellar Interferometer]] at the [[Mount Wilson Observatory]]. This allows the [[orbital elements]] to be computed, as well as the individual masses of the two stars. The stars complete their highly [[Elliptic orbit|elliptical orbit]] every 107 days.<ref name=apj356_641/>

The primary star has a [[stellar classification]] of A3&nbsp;V,<ref name=sb2/> which means it is an [[A-type main-sequence star]] that is generating energy through the [[thermonuclear fusion]] of hydrogen in its core region. The [[NStars]] project gives the star a spectral type of kA4&nbsp;hA5&nbsp;mA5&nbsp;Va under the revised [[MK spectral classification]] system.<ref name=aj126_4_2048/> The secondary star is a [[G-type main-sequence star]], with a [[stellar classification]] of G2V.<ref name=sb2/> It is about four magnitudes fainter than the primary; hence the energy output from the system is dominated by the primary star.<ref name=apj356_641/> In a few million years, as the primary evolves toward a [[red giant]], significant amounts of mass transfer to the secondary component is expected.<ref name=mnras384_1_173/>

The primary has been classified as a rapid rotator, with a [[stellar rotation|projected rotational velocity]] of 73&nbsp;km/s providing a lower bound on the [[azimuth]]al rotational velocity along the equator.<ref name=aaa463_2_671/> It may also be a mildly [[Am star]], which is a class of stars that show a peculiar spectrum with strong [[Spectral line|absorption lines]] from various elements and deficiencies in others. In β Arietis, these absorption lines are broadened because of the [[Doppler effect]] from the rotation, making analysis of the abundance patterns difficult.<ref name=aaass27_35/>

This system has been examined with the [[Spitzer Space Telescope]] for the presence of an [[infrared excess|excess emission of infrared]], which would indicate a disk of dust. However, no significant excess was detected.<ref name=aj126_4_2048/>

==Notes==
{{Notelist|notes =

{{Efn|name=rad|1=Calculated, using the [[Stefan-Boltzmann law]] and the star's [[effective temperature]] and luminosity, with respect to the [[Sun|solar]] nominal effective temperature of 5,772&nbsp;[[Kelvin|K]]:<math display="block">\sqrt{\biggl(\frac{5,772}{8,759}\biggr)^4 \cdot 10^{1.32}} = 1.985\ R_\odot.</math><math display="block">\sqrt{\biggl(\frac{5,772}{5,811}\biggr)^4 \cdot 10^{0.11}} = 1.12\ R_\odot.</math>}}

}}

==References==
{{reflist|refs=

<ref name=sb2>{{citation | postscript=.
 | title=A study of the physical properties of SB2s with both the visual and spectroscopic orbits
 | display-authors=1 | last1=Piccotti | first1=Luca
 | last2=Docobo | first2=José Ángel | last3=Carini | first3=Roberta
 | last4=Tamazian | first4=Vakhtang S. | last5=Brocato | first5=Enzo
 | last6=Andrade | first6=Manuel | last7=Campo | first7=Pedro P.
 | journal=[[Monthly Notices of the Royal Astronomical Society]]
 | volume=492 | issue=2 | pages=2709–2721 | date=February 2020
 | doi=10.1093/mnras/stz3616 | doi-access=free
 | bibcode=2020MNRAS.492.2709P | issn=0035-8711}}</ref>

<ref name=aaa474_2_653>{{citation | postscript=.
 | title=Validation of the new Hipparcos reduction
 | first=F. | last=van Leeuwen
 | journal=Astronomy and Astrophysics
 | volume=474 | issue=2 | pages=653–664 | date=November 2007
 | bibcode=2007A&A...474..653V | s2cid=18759600
 | doi=10.1051/0004-6361:20078357 | arxiv=0708.1752 }}</ref>

<ref name=aaass27_35>{{citation | postscript=.
 | title=Spectroscopic observations and curve-of-growth analyses of the four A stars omicron Peg, beta Ari, kappa Ari and 32 Vir
 | last=Mitton | first=J.
 | journal=Astronomy and Astrophysics Supplement Series
 | volume=27 | pages=35–46 | date=January 1977
 | bibcode=1977A&AS...27...35M }}</ref>

<ref name=gcsrv>{{citation | postscript=.
 | title=General Catalogue of Stellar Radial Velocities
 | last=Wilson | first=Ralph Elmer | year=1953
 | publisher=[[Carnegie Institution of Washington]]
 | location=Washington | bibcode=1953GCRV..C......0W }}</ref>

<ref name=aaa463_2_671>{{citation | postscript=.
 | title=Rotational velocities of A-type stars. III. Velocity distributions
 | display-authors=1 | last1=Royer | first1=F.
 | last2=Zorec | first2=J. | last3=Gómez | first3=A. E.
 | journal=Astronomy and Astrophysics
 | volume=463 | issue=2 | pages=671–682 |date=February 2007
 | doi=10.1051/0004-6361:20065224 | s2cid=18475298
 | bibcode=2007A&A...463..671R | arxiv=astro-ph/0610785 }}</ref>

<ref name=sps1966>{{citation | postscript=.
 | title=A System of photometric standards
 | display-authors=1 | last1=Gutierrez-Moreno | first1=Adelina
 | last2=Moreno | first2=H. | last3=Stock | first3=J.
 | last4=Torres | first4=C. | last5=Wroblewski | first5=H.
 | journal=Publications of the Department of Astronomy University of Chile
 | publisher=Publicaciones Universidad de Chile, Department de Astronomy
 | volume=1 | pages=1–17 | year=1966
 | bibcode=1966PDAUC...1....1G }}</ref>

<ref name=aj126_4_2048>{{citation | postscript=.
 | title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I
 | display-authors=1 | last1=Gray | first1=R. O.
 | last2=Corbally | first2=C. J. | last3=Garrison | first3=R. F.
 | last4=McFadden | first4=M. T. | last5=Robinson | first5=P. E.
 | journal=The Astronomical Journal
 | volume=126 | issue=4 | pages=2048–2059 | date=October 2003
 | doi=10.1086/378365 | s2cid=119417105
 | bibcode=2003AJ....126.2048G | arxiv=astro-ph/0308182 }}</ref>

<ref name=apj356_641>{{citation | postscript=.
 | title=Apparent orbit of the spectroscopic binary Beta Arietis with the time Mark III Stellar Interferometer
 | last1=Pan | first1=X. P. | last2=Shao | first2=M.
 | last3=Colavita | first3=M. M. | last4=Mozurkewich | first4=D.
 | last5=Simon | first5=R. S. | last6=Johnston | first6=K. J.
 | display-authors=1 | journal=Astrophysical Journal
 | volume=356 | pages=641–645 | year=1990
 | doi=10.1086/168870 | bibcode=1990ApJ...356..641P }}</ref>

<ref name=allen1899>{{citation | postscript=.
 | title=Star-Names and Their Meanings
 | last=Allen | first=Richard Hinckley | author-link=Richard Hinckley Allen
 | year=1899 | pages=81–82
 | publisher=G. E. Stechert | location=New York
 | url=https://books.google.com/books?id=5xQuAAAAIAAJ&pg=PA81 }}</ref>

<ref name=mnras384_1_173>{{citation | postscript=.
 | title=Nearby stars of the Galactic disc and halo - IV
 | last=Fuhrmann | first=Klaus
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=384 | issue=1 | pages=173–224 | date=February 2008
 | doi=10.1111/j.1365-2966.2007.12671.x | doi-access=free
 | bibcode=2008MNRAS.384..173F }}</ref>

<ref name=SIMBAD>{{citation | postscript=.
 | title=bet Ari -- Spectroscopic binary
 | work=SIMBAD | publisher=[[Centre de Données astronomiques de Strasbourg]]
 | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+Arietis
 | access-date=2011-12-29 }}</ref>

<ref name=Kunitzsch>{{citation | postscript=.
 | title=A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations
 | last1=Kunitzsch | first1=Paul | last2=Smart | first2=Tim
 | publisher=Sky Pub | location=Cambridge, Massachusetts
 | date=2006  | edition=2nd rev.
 | isbn=978-1-931559-44-7 }}</ref>

<ref name="IAU-CSN">{{citation
 | title=IAU Catalog of Star Names
 | publisher=International Astronomical Society
 | url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt
 | access-date=28 July 2016 | postscript=. }}</ref>

<ref name="WGSN">{{citation
 | url=https://www.iau.org/science/scientific_bodies/working_groups/280/
 | title=IAU Working Group on Star Names (WGSN)
 | publisher=[[International Astronomical Union]]
 | access-date=22 May 2016 | postscript=. }}</ref>

}}

==External links==
* [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?GJ%2080 GJ 80] Catalog
* [http://aladin.u-strasbg.fr/AladinPreview?-c=01+54+38.4091%2B20+48+28.926&ident=SV*+ZI+++101&submit=Aladin+previewer Image Beta Arietis]
* [https://web.archive.org/web/20060714122252/http://www.astro.uiuc.edu/~kaler/sow/sheratan.html Beta Arietis] by Professor Jim Kaler.
* [https://web.archive.org/web/20051112031853/http://www.ari.uni-heidelberg.de/aricns/cnspages/4c00161.htm ARICNS entry]
* [https://web.archive.org/web/20080926185552/http://www.purplehell.com/riddletools/stars.htm The Constellations and Named Stars]

{{Stars of Aries}}

{{Authority control}}

{{DEFAULTSORT:Beta Arietis}}
<!-- Physical properties -->
[[Category:A-type main-sequence stars]]
[[Category:G-type main-sequence stars]]
[[Category:Spectroscopic binaries]]
<!-- Catalogues/location -->
[[Category:Aries (constellation)]]
[[Category:Bayer objects|Arietis, Beta]]
[[Category:Bright Star Catalogue objects|0553]]
[[Category:Durchmusterung objects]]
[[Category:Flamsteed objects|Arietis, 06]]
[[Category:Gliese and GJ objects|0080]]
[[Category:Henry Draper Catalogue objects|011636]]
[[Category:Hipparcos objects|008903]]
[[Category:Stars with proper names|Sheratan]]