Skat (ster)

Skat
	Skat se ligging (in die rooi sirkel).
Sterrebeeld	Waterdraer
Bayer-naam	Delta Aquarii
Spektraaltipe	A3 V
Soort	Hoofreeksster
	Waarnemingsdata (Epog J2000)
Regte klimming	22h 54m 39.0125s
Deklinasie	-15° 49′ 14.953″
Skynmagnitude (m)	3,25
B-V-kleurindeks	+0,068
U-B-kleurindeks	+0,172
	Besonderhede
Massa (M☉)	2
Radius (R☉)	2,4
Ligsterkte (L☉)	26
Ouderdom (jaar)	0,3 miljard
Temperatuur (K)	9 000
	Ander name
	Skat, Scheat, 76 Aquarii, BD-16 6173, FK5 866, HD 216627, HIP 113136, HR 8709, SAO 165375.
Portaal	Sterrekunde

Skat (ook bekend as Delta Aquarii of δ Aqr) is die derde helderste ster in die sterrebeeld Waterdraer (Aquarius) en het ’n skynbare magnitude van 3,3.^[3] Dit kan dus met die blote oog gesien word. Dit is sowat 160 ligjare van die Son af geleë.^[2]

Eienskappe

Skat het ’n sterreklassifikasie van A3 V,^[1] en dus ’n massa van sowat twee keer en ’n radius van 2,4 keer dié van die Son.^[4] Die helderheid van sy buitenste atmosfeer af is 26 keer die Son s’n,^[4] met ’n effektiewe temperatuur van sowat 9 000 K.^[6] Dit gee dit die kenmerkende wit skynsel van ’n A-tipe ster. Dit draai teen ’n relatiewe hoë snelheid: sowat 81 km/s⁻¹.^[8]

Skat is versigtig waargeneem om te sien of dit ’n metgesel het, maar niks is gevind nie.^[5] Dit het ook nie ’n sterk infrarooistraling wat kan dui op die teenwoordigheid van materiaal wat om die ster sirkel nie.^[9] Die ster is moontlik lid van die Groot Beer- bewegende groep,^[10] wat ’n geraamde ouderdom van 500 miljoen jaar het.^[11]

Verwysings

↑ ^1,0 ^1,1 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1988MSS...C04....0H
↑ ^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 Celis S., L. (Oktober 1975), "Photoelectric photometry of late-type variable stars", Astronomy and Astrophysics Supplement Series 22: 9–17, Bibcode: 1975A&AS...22....9C
↑ ^4,0 ^4,1 ^4,2 ^4,3 ^4,4 Malagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series 85 (3): 1015–1019, Bibcode: 1990A&AS...85.1015M
↑ ^5,0 ^5,1 Ehrenreich, D. et al. (November 2010), "Deep infrared imaging of close companions to austral A- and F-type stars", Astronomy and Astrophysics 523: A73, doi:10.1051/0004-6361/201014763, Bibcode: 2010A&A...523A..73E
↑ ^6,0 ^6,1 Hill, G. M. (Februarie 1995), "Compositional differences among the A-type stars. 2: Spectrum synthesis up to V sin i = 110 km/s", Astronomy and Astrophysics 294 (2): 536–546, Bibcode: 1995A&A...294..536H
↑ "del Aqr -- Star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Delta+Aquarii, besoek op 2012-01-30
↑ Royer, F.; Zorec, J.; Gómez, A. E. (Februarie 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
↑ Su, K. Y. L. et al. (Desember 2006), "Debris Disk Evolution around A Stars", The Astrophysical Journal 653 (1): 675–689, doi:10.1086/508649, Bibcode: 2006ApJ...653..675S
↑ King, Jeremy R. et al. (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
↑ Monier, R. (November 2005), "Abundances of a sample of A and F-type dwarf members of the Ursa Major Group", Astronomy and Astrophysics 442 (2): 563–566, doi:10.1051/0004-6361:20053222, Bibcode: 2005A&A...442..563M

Eksterne skakels

Image Delta Aquarii Aladin image viewer
Skat (ster) 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

[houk1979-1] 1,0 ^1,1 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1988MSS...C04....0H

[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

[aaass22_9-3] 3,0 ^3,1 ^3,2 ^3,3 Celis S., L. (Oktober 1975), "Photoelectric photometry of late-type variable stars", Astronomy and Astrophysics Supplement Series 22: 9–17, Bibcode: 1975A&AS...22....9C

[aass85_3_1015-4] 4,0 ^4,1 ^4,2 ^4,3 ^4,4 Malagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series 85 (3): 1015–1019, Bibcode: 1990A&AS...85.1015M

[aaa523_A73-5] 5,0 ^5,1 Ehrenreich, D. et al. (November 2010), "Deep infrared imaging of close companions to austral A- and F-type stars", Astronomy and Astrophysics 523: A73, doi:10.1051/0004-6361/201014763, Bibcode: 2010A&A...523A..73E

[aaa294_2_536-6] 6,0 ^6,1 Hill, G. M. (Februarie 1995), "Compositional differences among the A-type stars. 2: Spectrum synthesis up to V sin i = 110 km/s", Astronomy and Astrophysics 294 (2): 536–546, Bibcode: 1995A&A...294..536H

[SIMBAD-7] "del Aqr -- Star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Delta+Aquarii, besoek op 2012-01-30

[aaa463_2_671-8] Royer, F.; Zorec, J.; Gómez, A. E. (Februarie 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

[apj653_1_675-9] Su, K. Y. L. et al. (Desember 2006), "Debris Disk Evolution around A Stars", The Astrophysical Journal 653 (1): 675–689, doi:10.1086/508649, Bibcode: 2006ApJ...653..675S

[aj125_4_1980-10] King, Jeremy R. et al. (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

[aaa442_2_563-11] Monier, R. (November 2005), "Abundances of a sample of A and F-type dwarf members of the Ursa Major Group", Astronomy and Astrophysics 442 (2): 563–566, doi:10.1051/0004-6361:20053222, Bibcode: 2005A&A...442..563M

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