Gacrux

	Gacrux
	Die Suiderkruis, met Gamma Crucis bo.
Sterrebeeld	Suiderkruis
Spektraaltipe	M3,5 III
Soort	Reusester
	Waarnemingsdata(Epog J2000)
Regte klimming	12h31m09.95961s
Deklinasie	-57° 06′ 47.5684″
Skynmagnitude(m)	1,64
Absolute magnitude(M)	-0,52
B-V-kleurindeks	1,59
U-B-kleurindeks	1,78
	Besonderhede
Massa(M☉)	1,3 ± 0,1
Radius (R☉)	84
Ligsterkte(L☉)	1 500
Temperatuur(K)	3 626
	Eienskappe
Veranderlikheid	Halfreëlmatig
	Ander name
	CD−56 4504,Gl470,HD108903,HIP61084, HR 4763, LTT 4752, SAO 240019
Portaal	Sterrekunde

Gacrux(ook bekend asGamma Crucisofγ Cru) is die naasterooireusaan dieSon:^[6]volgensparallaksmetingstydens dieHipparcos-sending sowat 88,6ligjareweg.^[2]

Met ’nskynbare magnitudevan 1,63^[9]is dit die derde helderstesterin die suidelikesterrebeeld Suiderkruis(Crux) en een van die helderstes aan die naghemel. ’n Lyn vanAlpha CentaurideurBeta Centaurilei tot binne ’n paar grade van dié ster.

Eienskappe

*Pulseringsperiodes*^[1]
Periode (dae)	Amplitude (magnitude)
12,1	0,016
15,1	0,027
16,5	0,016
54,8	0,026
82,7	0,015
104,9	0,016

Gacrux het ’nsterreklassifikasievan M3,5 III.^[1]Dit het diehoofreeksverlaat, maar is waarskynlik in dierooireusetakeerder as dieasimptotiese reusetak.^[6]Hoewel sy massa net 30% groter as die Son s’n is,^[5]het dit uitgesit tot 84 keer so groot.^[6]

Syligsterkteis sowat 1 500 keer^[7]dié van die Son. Met ’neffektiewe temperatuurvan 3 626K^[8]het Gamma Crucis ’n prominente rooi-oranje kleur, soos ander sterre met dié klassifikasie. Dit is ’nhalfreëlmatige veranderlikemet veelvoudige periodes.^[1](Sien tabel links.)

Die atmosfeer van die ster bevat baiebarium,wat verduidelik kan word aan die hand van materiaal wat van ’n verder ontwikklede ster af oorgedra word. So ’n metgesel sou gewoonlik ’nwitdwerggeword het.^[10]

Geen so ’n metgesel is egter nog ontdek nie. ’n Optiese metgesel met ’n skynbare magnitude van 6,4 lê wel sowat 2boogminuteweg teen ’n posisiehoek van 128 grade en kan met ’n verkyker gesien word.

Name

Die ster seBayer-naamis "Gamma Crucis". Die historiese naam, "Gacrux", is deur die sterrekundige Elijah Hinsdale Burritt gevestig.^[11]^[12]Dit is ’n verkorte vorm van Gamma Crucis.

In 2016 het dieInternasionale Astronomiese Uniese sternaamwerkgroep (WGSN) die naam "Gacrux" vir die ster goedgekeur.^[13]

Verwysings

↑^1,0^1,1^1,2^1,3^1,4Tabur, V.et al.(December 2009), "Long-term photometry and periods for 261 nearby pulsating M giants",Monthly Notices of the Royal Astronomical Society400(4): 1945–1961,doi:10.1111/j.1365-2966.2009.15588.x,Bibcode:2009MNRAS.400.1945T
↑^2,0^2,1^2,2van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction",Astronomy and Astrophysics474(2): 653–664,doi:10.1051/0004-6361:20078357,Bibcode:2007A&A...474..653V
↑^3,0^3,1^3,2Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system".CDS/ADC Collection of Electronic Catalogues.2237:0.Bibcode:2002yCat.2237....0D.
↑Elgarøy, Øystein; Engvold, Oddbjørn; Lund, Niels (March 1999), "The Wilson-Bappu effect of the MgII K line – dependence on stellar temperature, activity and metallicity",Astronomy and Astrophysics343:222–228,Bibcode:1999A&A...343..222E
↑^5,0^5,1Murdoch, Kaylene; Clark, M.; Hearnshaw, J. B. (January 1992), "The radial-velocity variability of Gamma Crucis",Monthly Notices of the Royal Astronomical Society254:27–29,doi:10.1093/mnras/254.1.27,Bibcode:1992MNRAS.254...27M
↑^6,0^6,1^6,2^6,3Ireland, M. J.et al.(May 2004), "Multiwavelength diameters of nearby Miras and semiregular variables",Monthly Notices of the Royal Astronomical Society350(1): 365–374,doi:10.1111/j.1365-2966.2004.07651.x,Bibcode:2004MNRAS.350..365I
↑^7,0^7,1Kaler, James B.,"GACRUX (Gamma Crucis)",Stars(University of Illinois),http://stars.astro.illinois.edu/sow/gacrux.html,besoek op 2012-03-03
↑^8,0^8,1Cohen, Martinet al.(November 1996), "Spectral Irradiance Calibration in the Infrared. VII.New Composite Spectra, Comparison with Model Atmospheres, and Far-Infrared Extrapolations",Astronomical Journal112:2274,doi:10.1086/118180,Bibcode:1996AJ....112.2274C
↑Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars".Communications of the Lunar and Planetary Laboratory.4(99): 99.Bibcode:1966CoLPL...4...99J.
↑Gomez, A. E.; Luri, X.; Grenier, S.et al.(March 1997), "Absolute magnitudes and kinematics of barium stars",Astronomy and Astrophysics319:881–885,Bibcode:1997A&A...319..881G
↑"Gacrux/Gamma Crucis 2?"(in Engels). SolStation.com.Geargiveervanaf die oorspronklike op 24 Oktober 2019.Besoek op3 November2011.
↑Lesikar, Arnold V."Gacrux".Dome Of The Sky. Geargiveer vanafdie oorspronklikeop 28 September 2011.Besoek op3 November2011.
↑"Bulletin of the IAU Working Group on Star Names, No. 1"(PDF).Besoek op28 Julie2016.

Eksterne skakels

"Gacrux/Gamma Crucis 2".SolStation.Besoek op10 September2008.
Gacrux opWikiSky:DSS2,SDSS,GALEX,IRAS,Hydrogen α,X-Ray,Astrophoto,Sky Map,Artikels en foto's
Hierdie artikel is vertaal uit dieEngelse Wikipedia

[mnras400_4_1945-1] 1,0^1,1^1,2^1,3^1,4Tabur, V.et al.(December 2009), "Long-term photometry and periods for 261 nearby pulsating M giants",Monthly Notices of the Royal Astronomical Society400(4): 1945–1961,doi:10.1111/j.1365-2966.2009.15588.x,Bibcode:2009MNRAS.400.1945T

[aaa474_2_653-2] 2,0^2,1^2,2van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction",Astronomy and Astrophysics474(2): 653–664,doi:10.1051/0004-6361:20078357,Bibcode:2007A&A...474..653V

[ducati-3] 3,0^3,1^3,2Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system".CDS/ADC Collection of Electronic Catalogues.2237:0.Bibcode:2002yCat.2237....0D.

[aaa343_222-4] Elgarøy, Øystein; Engvold, Oddbjørn; Lund, Niels (March 1999), "The Wilson-Bappu effect of the MgII K line – dependence on stellar temperature, activity and metallicity",Astronomy and Astrophysics343:222–228,Bibcode:1999A&A...343..222E

[mnras254_27-5] 5,0^5,1Murdoch, Kaylene; Clark, M.; Hearnshaw, J. B. (January 1992), "The radial-velocity variability of Gamma Crucis",Monthly Notices of the Royal Astronomical Society254:27–29,doi:10.1093/mnras/254.1.27,Bibcode:1992MNRAS.254...27M

[mnras350_1_365-6] 6,0^6,1^6,2^6,3Ireland, M. J.et al.(May 2004), "Multiwavelength diameters of nearby Miras and semiregular variables",Monthly Notices of the Royal Astronomical Society350(1): 365–374,doi:10.1111/j.1365-2966.2004.07651.x,Bibcode:2004MNRAS.350..365I

[kaler-7] 7,0^7,1Kaler, James B.,"GACRUX (Gamma Crucis)",Stars(University of Illinois),http://stars.astro.illinois.edu/sow/gacrux.html,besoek op 2012-03-03

[aj112_2274-8] 8,0^8,1Cohen, Martinet al.(November 1996), "Spectral Irradiance Calibration in the Infrared. VII.New Composite Spectra, Comparison with Model Atmospheres, and Far-Infrared Extrapolations",Astronomical Journal112:2274,doi:10.1086/118180,Bibcode:1996AJ....112.2274C

[clpl4-9] Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars".Communications of the Lunar and Planetary Laboratory.4(99): 99.Bibcode:1966CoLPL...4...99J.

[aaa319_881-10] Gomez, A. E.; Luri, X.; Grenier, S.et al.(March 1997), "Absolute magnitudes and kinematics of barium stars",Astronomy and Astrophysics319:881–885,Bibcode:1997A&A...319..881G

[11] "Gacrux/Gamma Crucis 2?"(in Engels). SolStation.com.Geargiveervanaf die oorspronklike op 24 Oktober 2019.Besoek op3 November2011.

[12] Lesikar, Arnold V."Gacrux".Dome Of The Sky. Geargiveer vanafdie oorspronklikeop 28 September 2011.Besoek op3 November2011.

[WGSN1-13] "Bulletin of the IAU Working Group on Star Names, No. 1"(PDF).Besoek op28 Julie2016.

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