Gamma Ceti

Gamma Ceti
	Die ligging van Gamma Ceti (in die rooi sirkel).
Sterrebeeld	Walvis
Spektraaltipe	A3 V / F3 V / K5
Soort	Veelvoudige ster
	Waarnemingsdata (Epog J2000)
Regte klimming	02h 43m 18.03910s
Deklinasie	+03° 14′ 08.9390″
Skynmagnitude (m)	3,47 ; (3,56/6,63/10,16)
B-V-kleurindeks	+0,09
U-B-kleurindeks	+0,07
	Besonderhede
Radius (R☉)	A: 1,9
Ouderdom (jaar)	A: 300 miljoen
Temperatuur (K)	A: 8 673
Rotasiespoed (km/s)	A: 186
Metaalinhoud [Fe/H]	A: 0,00 deks
	Eienskappe
Veelvoudigheid	Driedubbele ster
	Ander name
	86 Ceti, BD+02 422, HD 16970, HIP 12706, HR 804, SAO 110707.
Portaal	Sterrekunde

Gamma Ceti (γ Ceti, afgekort as Gamma Cet of γ Cet), tradisioneel bekend as Kaffaljidhma,^[9] is ’n veelvoudige ster in die sterrebeeld Walvis (Cetus). Dit het ’n skynbare magnitude van 3,47.^[3] Volgens parallaksmetings is dit sowat 80 ligjare van die Son af.^[2]

Eienskappe

Dit lyk of Gamma Ceti ’n driedubbele ster is. Die twee binneste sterre het ’n hoekskeiding van 2,6 boogsekondes. Die primêre komponent van dié paar het ’n skynbare magnitude van 3,6. Dit is ’n hoofreeksster met ’n sterreklassifikasie van A3 V. Die dowwer sekondêre komponent is ook ’n hoofreeksster, met ’n klassifikasie van F3 V en ’n magnitude van 6,6.^[1] Die kontrasterende kleure van hierdie twee sterre maak hulle gewild onder amateursterkykers. Die twee kan onder ideale toestande deur ’n klein teleskoop onderskei word, hoewel dit soms deur selfs ’n groter teleskoop moeilik is.^[10] Sowat 840 boogsekondes van hulle af is ’n dowwe ster met ’n magnitude van 10,2 en ’n klassifikasie van K5.

Gamma Ceti is sowat 300 miljoen jaar oud^[5] en dit lyk of dit lid is van die sterrestroom wat losweg verbind word met die Ursa Major- bewegende groep.^[11]

Name

Die ster se Bayer-naam is "Gamma Ceti" en sy Flamsteed-naam "86 Ceti". Die tradisionele naam, "Kaffaljidhma", kom van die Arabiese الكف الجذماء al-kaf al-jaðmāʼ "die kortgekapte hand".^[12]

In 2017 het die Internasionale Astronomiese Unie se sternaamwerkgroep (WGSN) die naam "Kaffaljidhma" vir die ster Gamma Ceti A goedgekeur^[13] omdat hulle eiename aan individuele sterre toegeken het eerder as aan stergroepe.

Verwysings

↑ ^1,0 ^1,1 ^1,2 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E
↑ ^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 ^3,3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99), Bibcode: 1966CoLPL...4...99J
↑ Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3 ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41 .
↑ ^5,0 ^5,1 Su, K. Y. L. et al. (December 2006), "Debris Disk Evolution around A Stars", The Astrophysical Journal 653 (1): 675–689, doi:10.1086/508649, Bibcode: 2006ApJ...653..675S
↑ ^6,0 ^6,1 Gray, R. O. et al. (2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–70, doi:10.1086/504637, Bibcode: 2006AJ....132..161G.
↑ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, doi:10.1051/0004-6361:20065224, Bibcode: 2007A&A...463..671R
↑ "LTT 10892 -- High proper-motion Star", SIMBAD Astronomical Object Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gamma+Ceti, besoek op 2012-03-04
↑ "IAU-CSN" (in Engels). Geargiveer vanaf die oorspronklike op 11 Mei 2020.
↑ Mollise, Rod (2006), The urban astronomer's guide: a walking tour of the cosmos for city sky watchers, Patrick Moore's practical astronomy series, Springer, p. 200, ISBN 1-84628-216-0, https://books.google.com/books?id=Z0mvZk0s_TMC&pg=PA200
↑ King, Jeremy R.; Villarreal, Adam R.; Soderblom, David R.; Gulliver, Austin F.; Adelman, Saul J. (April 2003), "Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group", The Astronomical Journal 125 (4): 1980–2017, doi:10.1086/368241, Bibcode: 2003AJ....125.1980K
↑ Allen, Richard Hinckley (1963), Star Names: Their Lore and Meaning (Dover ed.), University of Chicago, p. 160, http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Cetus*.html
↑ "Naming Stars" (in Engels). IAU.org. Geargiveer vanaf die oorspronklike op 4 Mei 2020. Besoek op 16 Desember 2017.

Eksterne skakels

Kaler, James B., "KAFFALJIDHMA (Gamma Ceti)", Stars (University of Illinois), http://stars.astro.illinois.edu/sow/kaffaljidhma.html, besoek op 2012-03-04
Gamma Ceti op WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Artikels en foto's
Hierdie artikel is vertaal uit die Engelse Wikipedia

[mnras389_2_869-1] 1,0 ^1,1 ^1,2 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E

[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

[clpl4_99-3] 3,0 ^3,1 ^3,2 ^3,3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99), Bibcode: 1966CoLPL...4...99J

[lang2006-4] Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3 ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41 .

[apj653_1_675-5] 5,0 ^5,1 Su, K. Y. L. et al. (December 2006), "Debris Disk Evolution around A Stars", The Astrophysical Journal 653 (1): 675–689, doi:10.1086/508649, Bibcode: 2006ApJ...653..675S

[Gray2006-6] 6,0 ^6,1 Gray, R. O. et al. (2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–70, doi:10.1086/504637, Bibcode: 2006AJ....132..161G.

[aaa463_2_671-7] Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, doi:10.1051/0004-6361:20065224, Bibcode: 2007A&A...463..671R

[SIMBAD-8] "LTT 10892 -- High proper-motion Star", SIMBAD Astronomical Object Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gamma+Ceti, besoek op 2012-03-04

[:0-9] "IAU-CSN" (in Engels). Geargiveer vanaf die oorspronklike op 11 Mei 2020.

[mollise2006-10] Mollise, Rod (2006), The urban astronomer's guide: a walking tour of the cosmos for city sky watchers, Patrick Moore's practical astronomy series, Springer, p. 200, ISBN 1-84628-216-0, https://books.google.com/books?id=Z0mvZk0s_TMC&pg=PA200

[aj125_4_1980-11] King, Jeremy R.; Villarreal, Adam R.; Soderblom, David R.; Gulliver, Austin F.; Adelman, Saul J. (April 2003), "Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group", The Astronomical Journal 125 (4): 1980–2017, doi:10.1086/368241, Bibcode: 2003AJ....125.1980K

[allen-12] Allen, Richard Hinckley (1963), Star Names: Their Lore and Meaning (Dover ed.), University of Chicago, p. 160, http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Cetus*.html

[IAU-LSN-13] "Naming Stars" (in Engels). IAU.org. Geargiveer vanaf die oorspronklike op 4 Mei 2020. Besoek op 16 Desember 2017.

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