View source for Astronomy:Sigma1 Gruis

{{Short description|Star in the constellation Grus}}
{{DISPLAYTITLE:Sigma<sup>1</sup> Gruis}}
{{other stars by Bayer designation|Sigma Gruis{{!}}σ Gruis}}
{{Starbox begin
 | name = Sigma<sup>1</sup> Gruis
}}
{{Starbox observe
 | epoch = [[Astronomy:J2000.0|J2000.0]]
 | equinox = [[Astronomy:J2000.0|J2000.0]] ([[Astronomy:International Celestial Reference System|ICRS]])
 | constell = [[Astronomy:Grus (constellation)|Grus]]
 | ra = {{RA|22|36|29.30230}}<ref name=GaiaDR2/>
 | dec = {{DEC|−40|34|57.7391}}<ref name=GaiaDR2/>
 | appmag_v = 6.26<ref name=Evans1966/>
}}
{{Starbox character
 | class = A3&nbsp;Vn<ref name=Evans1966/>
 | b-v = +0.12<ref name=Evans1966/>
 | u-b = 
 | r-i = 
 | variable = 
}}
{{Starbox astrometry
 | radial_v = {{Val|+6.9|3.4}}<ref name=Gontcharov2006/>
 | prop_mo_ra = +46.00<ref name=vanLeeuwen2007/>
 | prop_mo_dec = −72.64<ref name=vanLeeuwen2007/>
 | parallax = 14.2651
 | p_error = 0.0751
 | parallax_footnote = <ref name=GaiaDR2/>
 | absmag_v = +2.11<ref name=Anderson2012/>
}}
{{Starbox detail
 | source = <ref name=David2015/>
 | mass = 2.00
 | radius = 2.0<ref name=cadars/>
 | luminosity = 12<ref name=Anderson2012/>
 | temperature = {{Val|9230|314|fmt=commas}}
 | gravity = {{Val|4.24|0.14}}
 | metal_fe = 
 | rotational_velocity = {{Val|163.4|2.0}}<ref name=Diaz2011/>
 | age_myr = 194
}}
{{Starbox catalog
 | names = {{odlist | B=σ<sup>1</sup> Gru | CD=−41° 14959 | FK5=3811 | HD=214085 | HIP=111594 | HR=8600 | SAO=231211 }}<ref name=SIMBAD/>
}}
{{Starbox reference
 | Simbad = sig01+Gru
}}
{{starbox end}}
'''Sigma<sup>1</sup> Gruis''', a [[Social:Romanization of Greek|Latinization]] of '''σ<sup>1</sup> Gruis''', is a [[Astronomy:Star|star]] in the [[Astronomy:Constellation|constellation]] [[Astronomy:Grus (constellation)|Grus]]. It is a dim, white-hued star near the lower limit for visibility to the naked eye with an [[Astronomy:Apparent visual magnitude|apparent visual magnitude]] of 6.26.<ref name=Evans1966/> This object is located {{convert|70.1|pc|ly|order=flip}} distant from the Sun based on [[Astronomy:Stellar parallax|parallax]].<ref name=GaiaDR2/> The [[Astronomy:Radial velocity|radial velocity]] of this star is poorly constrained, but it appears to be drifting further away at the rate of +7&nbsp;km/s.<ref name=Gontcharov2006/>

This is an [[Astronomy:A-type main-sequence star|A-type main-sequence star]] with a [[Astronomy:Stellar classification|stellar classification]] of A2&nbsp;Vn; a star that is currently fusing its core [[Chemistry:Hydrogen|hydrogen]]. It has a relatively high rate of spin as indicated by the 'n' suffix, showing a projected rotational velocity of 163&nbsp;km/s.<ref name=Diaz2011/> This object is 194&nbsp;million years old with double the mass<ref name=David2015/> and radius of the Sun.<ref name=cadars/> The star is radiating 12<ref name=Anderson2012/> times the luminosity of the Sun from its [[Astronomy:Photosphere|photosphere]] at an [[Astronomy:Effective temperature|effective temperature]] of 9,230&nbsp;K.<ref name=David2015/> It is a source of [[Astronomy:X-ray astronomy|X-ray emission]], which may indicate it has an unseen stellar companion.<ref name=Schroeder2007/>

==References==
{{reflist|refs=

<ref name=GaiaDR2>{{cite DR2|6545396538377295232}}</ref>

<ref name=vanLeeuwen2007>{{citation
 | title=Validation of the new Hipparcos reduction
 | last1=van Leeuwen | first1=F.
 | journal=Astronomy and Astrophysics
 | volume=474 | issue=2 | pages=653–664 | date=2007
 | arxiv=0708.1752 | bibcode=2007A&A...474..653V
 | doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}</ref>

<ref name=Anderson2012>{{citation
 | title=XHIP: An extended hipparcos compilation
 | last1=Anderson | first1=E. | last2=Francis | first2=Ch.
 | journal=Astronomy Letters
 | volume=38 | issue=5 | pages=331 | year=2012
 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015
 | arxiv=1108.4971 | s2cid=119257644 | postscript=. }}</ref>

<ref name=cadars>{{citation | display-authors=1
 | last1=Pasinetti Fracassini | first1=L. E. | last2=Pastori | first2=L.
 | last3=Covino | first3=S. | last4=Pozzi | first4=A.
 | title=Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)
 | journal=Astronomy & Astrophysics
 | volume=367 | pages=521–24 | date=2001 | edition=3rd
 | bibcode=2001A&A...367..521P | doi=10.1051/0004-6361:20000451
 | arxiv=astro-ph/0012289 | s2cid=425754 | postscript=. }}</ref>

<ref name=Schroeder2007>{{citation
 | title=X-ray emission from A-type stars
 | last1=Schröder | first1=C. | last2=Schmitt | first2=J. H. M. M.
 | journal=Astronomy and Astrophysics | postscript=.
 | volume=475 | issue=2 | date=November 2007 | pages=677–684
 | doi=10.1051/0004-6361:20077429 | bibcode=2007A&A...475..677S | doi-access=free }}</ref>

<ref name=David2015>{{citation
 | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A.
 | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets
 | journal=The Astrophysical Journal
 | volume=804 | issue=2 | pages=146 | year=2015
 | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146
 | arxiv=1501.03154 | s2cid=33401607 | postscript=. }}</ref>

<ref name=Diaz2011>{{citation
 | last1=Díaz | first1=C. G. | last2=González | first2=J. F.
 | last3=Levato | first3=H. | last4=Grosso | first4=M.
 | title=Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum
 | display-authors=1 | journal=Astronomy & Astrophysics
 | volume=531 | page=A143 |date=July 2011
 | doi=10.1051/0004-6361/201016386 | bibcode=2011A&A...531A.143D
 | arxiv=1012.4858 | s2cid=119286673 | postscript=.}}</ref>

<ref name=Evans1966>{{citation
 | title=Fundamental data for Southern stars (6th list)
 | last1=Evans | first1=D. S. | year=1966
 | journal=Royal Observatory Bulletin | volume=110
 | page=185 | bibcode=1966RGOB..110..185E | postscript=. }}</ref>

<ref name=SIMBAD>{{cite simbad
 | title=sig01 Gru
 | accessdate=2017-06-24 | postscript=. }}</ref>

<ref name=Gontcharov2006>{{citation
 | last1=Gontcharov | first1=G. A.
 | title=Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system
 | journal=Astronomy Letters
 | volume=32| issue=11| pages=759–771| date=November 2006
 | doi=10.1134/S1063773706110065 | bibcode=2006AstL...32..759G
 | arxiv=1606.08053 | s2cid=119231169
 | postscript=. }}</ref>

}}

{{Stars of Grus|state=collapsed}}

{{DEFAULTSORT:Sigma1 Gruis}}
[[Category:A-type main-sequence stars]]
[[Category:Grus (constellation)]]
[[Category:Bayer objects|Gruis, Sigma1]]
[[Category:Henry Draper Catalogue objects|214085]]
[[Category:Hipparcos objects|111594]]
[[Category:Bright Star Catalogue objects|8600]]
[[Category:Durchmusterung objects]]

{{Sourceattribution|Sigma1 Gruis}}