Alpha Sextantis

Alpha Sextantis
	Die ligging van Alpha Sextantis (in die rooi sirkel).
Sterrebeeld	Sekstant
Spektraaltipe	A0 III
Soort	Reusester
	Waarnemingsdata (Epog J2000)
Regte klimming	10h 07m 56.29556s
Deklinasie	-0° 22′ 17.8621″
Skynmagnitude (m)	4,49
Absolute magnitude (M)	−0,29±0,21
B-V-kleurindeks	-0,04
U-B-kleurindeks	-0,07
	Besonderhede
Massa (M☉)	2,96±0,12
Radius (R☉)	4,5
Ligsterkte (L☉)	120
Ouderdom (jaar)	295
Temperatuur (K)	9 984
Afstand (ligjaar)	280
Rotasiespoed (km/s)	21
Metaalinhoud [Fe/H]	−0,03±0,18
	Ander name
	15 Sextantis, BD+00° 2615, FK5 2814, HD 87887, HIP 49641, HR 3981, SAO 137366
Portaal	Sterrekunde

Alpha Sextantis (afgekort as α Sex) is die helderste ster in die sterrebeeld Sekstant (Sextans).^[11] Met ’n skynbare magnitude van 4,49^[3] is dit met die blote oog sigbaar. Volgens parallaksmetings is dit sowat 280 ligjare van die Son af.^[2]

Dit word as ’n "ewenaarster" beskou omdat dit minder ’n kwartgraad suid van die hemelewenaar lê. In 1900 was dit 7 boogminute noord van die ewenaar. Vanweë ’n verskuiwing van die Aarde se draaias het dit in Desember 1923 na die Suidelike Halfrond geskuif.^[12]

Alpha Sextantis is ’n geëvolueerde A-tipe reusester met ’n sterreklassifikasie van A0 III.^[1] Sy massa is sowat drie keer^[4] en sy radius sowat 4,5 keer dié van die Son.^[5] Sy hoeveelheid metale (elemente swaarder as waterstof en helium) is soortgelyk aan die Son s'n.^[9] Dit straal omtrent 120 soveel ligsterkte as die Son uit met sy effektiewe temperatuur van 9 984 K.^[6] Alpha Sextantis is sowat 295 miljoen jaar oud.^[7]

Verwysings

↑ ^1,0 ^1,1 Cowley, A. et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal 74: 375–406, doi:10.1086/110819, Bibcode: 1969AJ.....74..375C.
↑ ^2,0 ^2,1 ^2,2 van Leeuwen, F. (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 Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (ongepubliseer), SIMBAD, Bibcode: 1986EgUBV........0M.
↑ ^4,0 ^4,1 ^4,2 Gerbaldi, M. et al. (Junie 1999), "Search for reference A0 dwarf stars: Masses and luminosities revisited with HIPPARCOS parallaxes", Astronomy and Astrophysics Supplement 137: 273–292, doi:10.1051/aas:1999248, Bibcode: 1999A&AS..137..273G.
↑ ^5,0 ^5,1 Pasinetti Fracassini, L. E. et al. (Februarie 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367: 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
↑ ^6,0 ^6,1 ^6,2 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
↑ ^7,0 ^7,1 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.
↑ Royer, F. et al. (Oktober 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393: 897–911, doi:10.1051/0004-6361:20020943, Bibcode: 2002A&A...393..897R.
↑ ^9,0 ^9,1 Pintado, O. I.; Adelman, S. J. (Augustus 2003), "Elemental abundance analyses with the EBASIM spectrograph of the 2.1-m CASLEO Observatory Telescope. I. The late B and early A stars vec xi Octantis, alpha Sextantis, and 68 Tauri", Astronomy and Astrophysics 406: 987–994, doi:10.1051/0004-6361:20030813, Bibcode: 2003A&A...406..987P.
↑ "alf Sex". Simbad. Centre de données astronomiques de Strasbourg. Besoek op 12 Desember 2016.
↑ "Sextans (abbr. Sex, gen. Sextantis)", The Internet Encyclopedia of Science, http://www.daviddarling.info/encyclopedia/S/Sex.html, besoek op 2016-12-12.
↑ Kaler, James B., "Alpha Sextantis", Stars (University of Illinois), http://stars.astro.illinois.edu/sow/alphasext.html, besoek op 2016-12-12.

Eksterne skakels

Astronomy Knowledge Database
Hierdie artikel is vertaal uit die Engelse Wikipedia

[Cowley1969-1] 1,0 ^1,1 Cowley, A. et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal 74: 375–406, doi:10.1086/110819, Bibcode: 1969AJ.....74..375C.

[vanLeeuwen2007-2] 2,0 ^2,1 ^2,2 van Leeuwen, F. (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.

[Mermilliod1986-3] 3,0 ^3,1 ^3,2 ^3,3 Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (ongepubliseer), SIMBAD, Bibcode: 1986EgUBV........0M.

[Gerbaldi1999-4] 4,0 ^4,1 ^4,2 Gerbaldi, M. et al. (Junie 1999), "Search for reference A0 dwarf stars: Masses and luminosities revisited with HIPPARCOS parallaxes", Astronomy and Astrophysics Supplement 137: 273–292, doi:10.1051/aas:1999248, Bibcode: 1999A&AS..137..273G.

[PasinettiFracassini2001-5] 5,0 ^5,1 Pasinetti Fracassini, L. E. et al. (Februarie 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367: 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.

[Mcdonald2012-6] 6,0 ^6,1 ^6,2 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.

[Su2006-7] 7,0 ^7,1 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.

[Royer2002-8] Royer, F. et al. (Oktober 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393: 897–911, doi:10.1051/0004-6361:20020943, Bibcode: 2002A&A...393..897R.

[Pintado2003-9] 9,0 ^9,1 Pintado, O. I.; Adelman, S. J. (Augustus 2003), "Elemental abundance analyses with the EBASIM spectrograph of the 2.1-m CASLEO Observatory Telescope. I. The late B and early A stars vec xi Octantis, alpha Sextantis, and 68 Tauri", Astronomy and Astrophysics 406: 987–994, doi:10.1051/0004-6361:20030813, Bibcode: 2003A&A...406..987P.

[SIMBAD-10] "alf Sex". Simbad. Centre de données astronomiques de Strasbourg. Besoek op 12 Desember 2016.

[Darling-11] "Sextans (abbr. Sex, gen. Sextantis)", The Internet Encyclopedia of Science, http://www.daviddarling.info/encyclopedia/S/Sex.html, besoek op 2016-12-12.

[Kaler-12] Kaler, James B., "Alpha Sextantis", Stars (University of Illinois), http://stars.astro.illinois.edu/sow/alphasext.html, besoek op 2016-12-12.

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