Mirzam

Mirzam
	Mirzam se ligging (in die rooi sirkel).
Sterrebeeld	Groot Hond
Bayer-naam	Beta Canis Majoris
Spektraaltipe	B1 II-III
Soort	Reusester/Helder reus
	Waarnemingsdata (Epog J2000)
Regte klimming	06h 22m 41.98535s
Deklinasie	-17° 57′ 21.3073″
Skynmagnitude (m)	1,985 (1.97 - 2.01)
Absolute magnitude (M)	-4,1
B-V-kleurindeks	-0,235
U-B-kleurindeks	-0,99
	Besonderhede
Massa (M☉)	13,5 ± 0,5
Radius (R☉)	9,7 ± 1,3
Ligsterkte (L☉)	26 600
Ouderdom (jaar)	12,4 ± 0,7 miljoen
Temperatuur (K)	23 150
Afstand (ligjaar)	500
Rotasiespoed (km/s)	31 ± 5
Metaalinhoud [Fe/H]	0,04 ± 0,10
	Eienskappe
Veranderlikheid	β Cep
	Ander name
	Murzim, Mirza, 2 Canis Majoris, HR 2294, BD-17°1467, HD 44743, SAO 151428, FK5 243, HIP 30324, GC 8223, CCDM 06227-1757
Portaal	Sterrekunde

Mirzam (ook bekend as Beta Canis Majoris of β CMa) is ’n ster in die sterrebeeld Groot Hond (Canis Major). Met sy gemiddelde skynbare magnitude van 1,985 is dit een van die helderste sterre in die naglug. Volgens parallaksmetings is dit sowat 500 ligjare van die Son af.^[2]

Eienskappe

Mirzam is ’n Beta Cephei-veranderlike^[9] met ’n skynbare magnitude wat oor ’n tydperk van ses uur wissel tussen 1,97 en 2,01, ’n wisseling wat te klein is om met die blote oog waar te neem. Die wisselings is die gevolg van periodieke pulse in sy buitenste laag.

Sy massa is sowat 13 tot 14 keer dié van die Son^[6] en sy radius 8 tot 11 keer die Son s'n.^[7] Sy effektiewe temperatuur is sowat 23 150 K, wat baie hoër as die Son s’n van 5 778 K is. Sy temperatuur gee dit die tipiese blouwit kleur van ’n B-tipe ster.^[8]^[12] Mirzam se geraamde ouderdom is 12 miljoen tot 13 miljoen jaar. Dit het die waterstof in sy kern opgebruik en ’n reusester geword. Sy sterreklassifikasie van B1 II-III^[1] dui aan sy spektrum lê tussen dié van ’n reusester en helder reus.

Name

Die ster se Bayer-naam is "Beta Canis Majoris". Sy tradisionele name, "Mirzam" "Al-Murzim" of "Murzim",^[10] kom van die Arabiese مرزم, "die voorloper", wat waarskynlik verwys na sy posisie as voorloper van Sirius in die naglug (hy kom voor Sirius op). In 2016 het die Internasionale Astronomiese Unie se sternaamwerkgroep (WGSN) die naam "Mirzam" vir die ster goedgekeur.^[13]

Kultuuraspek

Mirzam verskyn op die vlag van Brasilië en simboliseer die staat Amapá.^[14]

Verwysings

↑ ^1,0 ^1,1 Abt, Helmut A. et al. (Julie 2002), "Rotational Velocities of B Stars", The Astrophysical Journal 573 (1): 359–365, doi:10.1086/340590, Bibcode: 2002ApJ...573..359A
↑ ^2,0 ^2,1 ^2,2 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V
↑ ^3,0 ^3,1 ^3,2 Cousins, A. W. J. (1972), "UBV Photometry of Some Very Bright Stars", Monthly Notes of the Astronomical Society of Southern Africa 31: 69, Bibcode: 1972MNSSA..31...69C
↑ Balona, L. A.; Bregman, L.; Letsapa, B. A.; Magoro, B. T.; Walsh, S. E. (1996). "The Pulsation Frequencies of beta CMa". Information Bulletin on Variable Stars. 4313: 1. Bibcode:1996IBVS.4313....1B.
↑ Shobbrook, R. R.; Handler, G.; Lorenz, D.; Mogorosi, D. (2006). "Photometric studies of three multiperiodic β Cephei stars: β CMa, 15 CMa and KZ Mus". Monthly Notices of the Royal Astronomical Society. 369 (1): 171–181. arXiv:astro-ph/0603754. Bibcode:2006MNRAS.369..171S. doi:10.1111/j.1365-2966.2006.10289.x.
↑ ^6,0 ^6,1 ^6,2 ^6,3 ^6,4 Mazumdar, A. et al. (November 2006), "An asteroseismic study of the β Cephei star β Canis Majoris", Astronomy and Astrophysics 459 (2): 589–596, doi:10.1051/0004-6361:20064980, Bibcode: 2006A&A...459..589M
↑ ^7,0 ^7,1 ^7,2 Hubrig, S. et al. (Junie 2006), "Discovery of magnetic fields in the βCephei star ξ1 CMa and in several slowly pulsating B stars*", Monthly Notices of the Royal Astronomical Society: Letters 369 (1): L61–L65, doi:10.1111/j.1745-3933.2006.00175.x, Bibcode: 2006MNRAS.369L..61H
↑ ^8,0 ^8,1 Zorec, J. et al. (Julie 2009), "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff", Astronomy and Astrophysics 501 (1): 297–320, doi:10.1051/0004-6361/200811147, Bibcode: 2009A&A...501..297Z
↑ ^9,0 ^9,1 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/gcvs. Oorspronklik In: 2009yCat....102025S. 1: 02025. Bibcode:2009yCat....102025S.
↑ ^10,0 ^10,1 Allen, Richard Hinckley (1899), "Star-names and their meanings", New York: 129–130, Bibcode: 1899sntm.book.....A, https://books.google.com/books?id=5xQuAAAAIAAJ&pg=PA129
↑ "V* bet CMa -- Variable Star of beta Cep type", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+Canis+Majoris, besoek op 2012-01-02
↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, archived from the original on 2012-03-10, https://www.webcitation.org/6630AbtJZ?url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, besoek op 2012-01-16
↑ "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Besoek op 28 Julie 2016.
↑ "Astronomy of the Brazilian Flag" (in Engels). FOTW Flags Of The World website. Geargiveer vanaf die oorspronklike op 4 Julie 2017.

Ander bronne

Makemson, Maud Worcester (1941), The Morning Star Rises: An Account of Polynesian Astronomy, Yale University Press
Hierdie artikel is vertaal uit die Engelse Wikipedia

[apj573_1_359-1] 1,0 ^1,1 Abt, Helmut A. et al. (Julie 2002), "Rotational Velocities of B Stars", The Astrophysical Journal 573 (1): 359–365, doi:10.1086/340590, Bibcode: 2002ApJ...573..359A

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

[mnassa31_69-3] 3,0 ^3,1 ^3,2 Cousins, A. W. J. (1972), "UBV Photometry of Some Very Bright Stars", Monthly Notes of the Astronomical Society of Southern Africa 31: 69, Bibcode: 1972MNSSA..31...69C

[4] Balona, L. A.; Bregman, L.; Letsapa, B. A.; Magoro, B. T.; Walsh, S. E. (1996). "The Pulsation Frequencies of beta CMa". Information Bulletin on Variable Stars. 4313: 1. Bibcode:1996IBVS.4313....1B.

[5] Shobbrook, R. R.; Handler, G.; Lorenz, D.; Mogorosi, D. (2006). "Photometric studies of three multiperiodic β Cephei stars: β CMa, 15 CMa and KZ Mus". Monthly Notices of the Royal Astronomical Society. 369 (1): 171–181. arXiv:astro-ph/0603754. Bibcode:2006MNRAS.369..171S. doi:10.1111/j.1365-2966.2006.10289.x.

[aaa459_2_589-6] 6,0 ^6,1 ^6,2 ^6,3 ^6,4 Mazumdar, A. et al. (November 2006), "An asteroseismic study of the β Cephei star β Canis Majoris", Astronomy and Astrophysics 459 (2): 589–596, doi:10.1051/0004-6361:20064980, Bibcode: 2006A&A...459..589M

[mnras369_1_L61-7] 7,0 ^7,1 ^7,2 Hubrig, S. et al. (Junie 2006), "Discovery of magnetic fields in the βCephei star ξ1 CMa and in several slowly pulsating B stars*", Monthly Notices of the Royal Astronomical Society: Letters 369 (1): L61–L65, doi:10.1111/j.1745-3933.2006.00175.x, Bibcode: 2006MNRAS.369L..61H

[aaa501_1_297-8] 8,0 ^8,1 Zorec, J. et al. (Julie 2009), "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff", Astronomy and Astrophysics 501 (1): 297–320, doi:10.1051/0004-6361/200811147, Bibcode: 2009A&A...501..297Z

[gcvs-9] 9,0 ^9,1 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/gcvs. Oorspronklik In: 2009yCat....102025S. 1: 02025. Bibcode:2009yCat....102025S.

[allen1899-10] 10,0 ^10,1 Allen, Richard Hinckley (1899), "Star-names and their meanings", New York: 129–130, Bibcode: 1899sntm.book.....A, https://books.google.com/books?id=5xQuAAAAIAAJ&pg=PA129

[SIMBAD-11] "V* bet CMa -- Variable Star of beta Cep type", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+Canis+Majoris, besoek op 2012-01-02

[csiro-12] "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, archived from the original on 2012-03-10, https://www.webcitation.org/6630AbtJZ?url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, besoek op 2012-01-16

[WGSN1-13] "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Besoek op 28 Julie 2016.

[14] "Astronomy of the Brazilian Flag" (in Engels). FOTW Flags Of The World website. Geargiveer vanaf die oorspronklike op 4 Julie 2017.

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