Википедија

Alfa Kentauri

Alfa Kentauri ili α Cen ili Toliman je najsjajnija zvezda u sazvežđu Kentaur (Centaurus), koje je vidljivo od januara do jula, a kulminira tokom aprila i nije vidljivo sa severne polulopte na geografskim širinama većim od 30°. Alfa Kentaur je Zemlji najbliža zvezda, posle Sunca.

Alfa Kentauri AB[note 1]

Alfa Kentauri AB je najsvetlija zveza vidljiva s leve strane, koja formira trozvezdani sistem sa Proksima Kentauri, zaokruženom crveno. Najsvetliji zvezdani sistem sa desne strane je Beta Kentauri.
Opservacioni podaci
Epoha J2000.0      Ravnodnevnica J2000.0
Sazvežđe Kentauri
Alfa Kentauri A
Rektascenzija 14h 39m 36.49400s[1]
Deklinacija −60° 50′ 02.3737″[1]
Prividna magnituda (V) +0.01[2]
Alfa Kentauri B
Rektascenzija 14h 39m 35.06311s[1]
Deklinacija −60° 50′ 15.0992″[1]
Prividna magnituda (V) +1.33[2]
Karakteristike
A
Spektralni tip G2V[3]
U−B indeks boja +0.24[2]
B−V indeks boja +0.71[2]
B
Spektralni tip K1V[3]
U−B indeks boja +0.68[2]
B−V indeks boja +0.88[2]
Astrometrija
A
Radijalna brzina (Rv)−21,4±0,76[4] km/s
Sopstveno kretanje (μ) RA: −3679.25[1] mas/g
Dek.: 473.67[1] mas/g
Paralaksa (π)754.81 ± 4.11[1] mas
Rastojanje4.37[5] sg
Apsolutna magnituda (MV)4.38[6]
B
Radijalna brzina (Rv)−18,6±1,64[4] km/s
Sopstveno kretanje (μ) RA: −3614.39[1] mas/g
Dek.: 802.98[1] mas/g
Paralaksa (π)754.81 ± 4.11[1] mas
Rastojanje4.37[5] sg
Apsolutna magnituda (MV)5.71[6]
Detalji
Alfa Kentauri A
Masa1.100[7] M☉
Poluprečnik1,2234±0,0053[8] R☉
Luminoznost1.519[7] L☉
Površinska gravitacija (log g)4.30[9] cgs
Temperatura5,790[7] K
Metaličnost [Fe/H]0.20[7] dex
Rotacija22±5,9 d[10]
Rotaciona brzina (v sin i)2,7±0,7[10] km/s
Alfa Kentauri B
Masa0.907[7] M☉
Poluprečnik0,8632±0,0037[8] R☉
Luminoznost0.5002[7] L☉
Površinska gravitacija (log g)4.37[9] cgs
Temperatura5,260[7] K
Metaličnost0.23[7]
Rotacija36[11] days
Rotaciona brzina (v sin i)1,1±0,8[12] km/s
Starost5,3±0,3[13] Gyr
Orbita[14]
PrimarnaA
KompanjonB
Period (P)79,91±0,011 g
Velika poluosa (a)17,57±0,022″
Ekscentricitet (e)0,5179±0,00076
Inklinacija (i)79,205±0,041°
Longituda uzlaznog čvora (Ω)204,85±0,084°
Apsidna epoha (T)1875,66±0,012
Argument perihela (ω)
(sekundarni)		231,65±0,076°
Druge oznake
Gliese 559, FK5 538, CD−60°5483, CCDM J14396-6050, GC 19728
α Cen A: Rigil Kentaurus, Rigil Kent, α1 Centauri, HR 5459, HD 128620, GCTP 3309.00, LHS 50, SAO 252838, HIP 71683
α Cen B: Toliman, α2 Centauri, HR 5460, HD 128621, LHS 51, HIP 71681
Referentne baze podataka
SIMBADAB
A
B
Ekstrasolarna arhivadata
ARICNSdata
Enciklopedija
ekstrasolarnih planeta		data
Alfa Kentauri

Iako je najbliža zvezda Zemlji (posle Sunca) tek je peta po sjaju sa svojom prividnom magnitudom 0,06, a nalazi se na 4,3 svetlosne godine od Zemlje. Koordinate Alfa Kentaura u sfernom nebeskom ekvatorskom koordinatnom sistemu su 14 sati i 36 minuta (rektascenzija) i -60°38' (deklinacija). Ova zvezda pripada spektralnoj klasi G2 (prema Harvardskoj spektralnoj klasifikaciji), kao i Sunce.

Alfa Kentauri je trojni sistem, čiji član je i Proksima Kentauri, najbliža zvezda Suncu.

Procene rastojanja uredi

Alfa Kentauri AB procene rastojanja
Izvor Paralaksa (mas) Rastojanje (pc) Rastojanje (ly) Rastojanje (Pm) Reference
Henderson (1839) 1160±110 0,86+0,09
−0,07 		2.57 ± 0.53 26,6+2,8
−2,3 		[15]
Henderson (1842) 912,8±64 1.03 ± 0.15 3.34 ± 0.5 33,8+2,5
−2,2 		[16]
Maklir (1851) 918,7±34 1,09±0,04 3,55+0,14
−0,13 		32.4 ± 2.5 [17]
Moesta (1868) 880±68 1,14+0,10
−0,08 		3,71+0,31
−0,27 		35,1+2,9
−2,5 		[18]
Gil & Elkin (1885) 750±10 1,333±0,018 4,35±0,06 41,1+0,6
−0,5 		[19]
Roberts (1895) 710±50 1.32 ± 0.2 4.29 ± 0.65 43,5+3,3
−2,9 		[20]
Vuli et al. (1970) 743±7 1,346±0,013 4,39±0,04 41,5±0,4 [21]
Glis & Jahreib (1991) 749,0±4,7 1,335±0,008 4,355±0,027 41,20±0,26 [22]
van Altena et al. (1995) 749,9±5,4 1,334±0,010 4,349+0,032
−0,031 		41,15+0,30
−0,29 		[23]
Periman et al. (1997) (A and B) 742,12±1,40 1,3475±0,0025 4,395±0,008 41,58±0,08 [24]

[25] [26] [27]

Sederhjelm (1999) 747,1±1,2 1,3385+0,0022
−0,0021 		4,366±0,007 41,30±0,07 [28]
van Liuven (2007) (A) 754,81±4,11 1,325±0,007 4,321+0,024
−0,023 		40,88±0,22 [29]
van Liuven (2007) (B) 796,92±25,90 1,25±0,04 4,09+0,14
−0,13 		37.5 ± 2.5 [30]
RECONS TOP100 (2012) 747,23±1,17[note 2] 1,3383±0,0021 4,365±0,007 41,29±0,06 [31]

Napomene uredi

  1. ^ Proxima Centauri is gravitationally bound to the α Centauri system, but for practical and historical reasons it is described in detail in its own article.
  2. ^ Weighted parallax based on parallaxes from van Altena et al. (1995) and Söderhjelm (1999).

Reference uredi

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  5. ^ a b Wilkinson, John (2012). „The Sun and Stars”. New Eyes on the Sun . Astronomers' Universe. str. 219–236. ISBN 978-3-642-22838-4. ISSN 1614-659X. doi:10.1007/978-3-642-22839-1_10. 
  6. ^ a b P. A. Wiegert; M. J. Holman (1997). „The stability of planets in the Alpha Centauri system”. The Astronomical Journal. 113: 1445 — 1450. Bibcode:1997AJ....113.1445W. arXiv:astro-ph/9609106  . doi:10.1086/118360. 
  7. ^ a b v g d đ e ž Thévenin, F.; Provost, J.; Morel, P.; Berthomieu, G.; Bouchy, F.; Carrier, F. (2002). „Asteroseismology and calibration of alpha Cen binary system”. Astronomy & Astrophysics. 392: L9. Bibcode:2002A&A...392L...9T. arXiv:astro-ph/0206283  . doi:10.1051/0004-6361:20021074. 
  8. ^ a b Kervella, P.; Bigot, L.; Gallenne, A.; Thévenin, F. (januar 2017). „The radii and limb darkenings of α Centauri A and B. Interferometric measurements with VLTI/PIONIER”. Astronomy & Astrophysics. 597. A137. Bibcode:2017A&A...597A.137K. arXiv:1610.06185  . doi:10.1051/0004-6361/201629505. 
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  10. ^ a b Bazot, M.; et al. (2007). „Asteroseismology of α Centauri A. Evidence of rotational splitting”. Astronomy and Astrophysics. 470 (1): 295—302. Bibcode:2007A&A...470..295B. arXiv:0706.1682  . doi:10.1051/0004-6361:20065694. 
  11. ^ DeWarf, L.; Datin, K.; Guinan, E. (2010). „X-ray, FUV, and UV Observations of α Centauri B: Determination of Long-term Magnetic Activity Cycle and Rotation Period”. The Astrophysical Journal. 722 (1): 343—357. Bibcode:2010ApJ...722..343D. arXiv:1009.1652  . doi:10.1088/0004-637X/722/1/343. 
  12. ^ Raassen, A. J. J.; Ness, J.-U.; Mewe, R.; Van Der Meer, R. L. J.; Burwitz, V.; Kaastra, J. S. (2003). „Chandra-LETGS X-ray observation of α Centauri: A nearby (G2V + K1V) binary system”. Astronomy & Astrophysics. 400 (2): 671—678. Bibcode:2003A&A...400..671R. doi:10.1051/0004-6361:20021899  . 
  13. ^ Joyce, M.; Chaboyer, B. (2018). „Classically and Asteroseismically Constrained 1D Stellar Evolution Models of α Centauri a and B Using Empirical Mixing Length Calibrations”. The Astrophysical Journal. 864 (1): 99. Bibcode:2018ApJ...864...99J. arXiv:1806.07567  . doi:10.3847/1538-4357/aad464. 
  14. ^ Pourbaix, D.; et al. (2002). „Constraining the difference in convective blueshift between the components of alpha Centauri with precise radial velocities”. Astronomy and Astrophysics. 386 (1): 280—285. Bibcode:2002A&A...386..280P. arXiv:astro-ph/0202400  . doi:10.1051/0004-6361:20020287. 
  15. ^ Henderson, H. (1839). „On the parallax of α Centauri” (PDF). Monthly Notices of the Royal Astronomical Society. 4 (19): 168—169. Bibcode:1839MNRAS...4..168H. doi:10.1093/mnras/4.19.168. 
  16. ^ Henderson, T. (1842). „The Parallax of α Centauri, deduced from Mr. Maclear's Observations at the Cape of Good Hope, in the Years 1839 and 1840”. Memoirs of the Royal Astronomical Society. 12: 370—371. Bibcode:1842MmRAS..12..329H. 
  17. ^ Maclear, T. (1851). „Determination of the Parallax of α 1 and α2 Centauri, from Observations made at the Royal Observatory, Cape of Good Hope, in the Years 1842-3-4 and 1848”. Memoirs of the Royal Astronomical Society. 20: 98. Bibcode:1851MmRAS..20...70M. 
  18. ^ Moesta, C. G. (1868). „Bestimmung der Parallaxe von α und β Centauri” [Determining the parallax of α and β Centauri]. Astronomische Nachrichten (na jeziku: German). 71 (8): 117—118. Bibcode:1868AN.....71..113M. doi:10.1002/asna.18680710802. 
  19. ^ Gill, David; Elkin, W.L. (1885). „Heliometer-Determinations of Stellar Parallax in the Southern Hemisphere”. Memoirs of the Royal Astronomical Society. 48: 188. Bibcode:1885MmRAS..48....1G. 
  20. ^ Roberts, Alex W. (1895). „Parallax of α Centauri from Meridian Observations 1879–1881”. Astronomische Nachrichten. 139 (12): 189—190. Bibcode:1895AN....139..177R. doi:10.1002/asna.18961391202. 
  21. ^ Woolley, R.; Epps, E. A.; Penston, M. J.; Pocock, S. B. (1970). „Woolley 559”. Catalogue of Stars within 25 Parsecs of the Sun. 5: ill. Bibcode:1970ROAn....5.....W. Arhivirano iz originala 08. 10. 2017. g. Pristupljeno 9. 5. 2014. 
  22. ^ Gliese, W.; Jahreiß, H. (1991). „Gl 559”. Preliminary Version of the Third Catalogue of Nearby Stars. Astronomische Rechen-Institut. Pristupljeno 9. 5. 2014. 
  23. ^ Van Altena, W. F.; Lee, J. T.; Hoffleit, E. D. (1995). „GCTP 3309”. The General Catalogue of Trigonometric Stellar Parallaxes (Fourth izd.). Yale University Observatory. Pristupljeno 9. 5. 2014. 
  24. ^ Perryman; et al. (1997). „HIP 71683”. The Hipparcos and Tycho Catalogues. Pristupljeno 9. 5. 2014. 
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  28. ^ Söderhjelm, Staffan (1999). „HIP 71683”. Visual binary orbits and masses post Hipparcos. Pristupljeno 9. 5. 2014. 
  29. ^ van Leeuwen, Floor (2007). „HIP 71683”. Validation of the new Hipparcos reduction. 
  30. ^ van Leeuwen, Floor (2007). „HIP 71681”. Validation of the new Hipparcos reduction. 
  31. ^ „The One Hundred Nearest Star Systems”. Research Consortium On Nearby Stars. Georgia State University. 7. 9. 2007. Arhivirano iz originala 12. 11. 2007. g. Pristupljeno 2. 12. 2014. 

Spoljašnje veze uredi

 
Alfa Kentauri na Vikimedijinoj ostavi.

Hipotetične planete ili eksploracija uredi

Preuzeto iz „https://sr.wikipedia.org/w/index.php?title=Алфа_Кентаури&oldid=25891278”