Alfa Kentavra
Alfa Kentavra (α Kentavra / α Cen), znana tudi kot Rigil Kentaurus, Rigil Kent ali Toliman, je najsvetlejša zvezda v južnem ozvezdju Kentavra. Zvezda je dvozvezdje, Alfa Kentavra AB (α Cen AB). Z golim očesom jo vidimo kot eno zvezdo, s svojim navideznim sijem pa je na tretjem mestu najsvetlejših zvezd na nočnem nebu.
 Lega Alfe Kentavra | |
| Opazovalni podatki Epoha J2000.0 Enakonočje J2000.0 | |
|---|---|
| Ozvezdje | Kentaver |
| Alpha Centauri A | |
| Rektascenzija | 14h 39m 36,49400s[1] |
| Deklinacija | –60° 50′ 02,3737″[1] |
| Navidezni sij (V) | +0.01[2] |
| Alpha Centauri B | |
| Rektascenzija | 14h 39m 35,06311s[1] |
| Deklinacija | –60° 50′ 15,0992″[1] |
| Navidezni sij (V) | +1.33[2] |
| Značilnosti | |
| A | |
| Spektralni razred | G2V[3] |
| U−B Barvni indeks | +0,24[2] |
| B−V Barvni indeks | +0,71[2] |
| B | |
| Spektralni razred | K1V[3] |
| U−B Barvni indeks | +0,68[2] |
| B−V Barvni indeks | +0,88[2] |
| Astrometrija | |
| A | |
| Radialna hitrost (Rv) | −214±076[4] km/s |
| Lastno gibanje (μ) | RA: −3679,25[1] mas/l Dec.: 473,67[1] mas/l |
| Paralaksa (π) | 754,81 ± 4,11[1] mas |
| Oddaljenost | 4,37[5] sv. l. |
| Absolutni izsev (MV) | 4,38[6] |
| B | |
| Radialna hitrost (Rv) | −18,6±1,64[4] km/s |
| Lastno gibanje (μ) | RA: −3614,39[1] mas/l Dec.: 802,98[1] mas/l |
| Paralaksa (π) | 754,81 ± 4,11[1] mas |
| Oddaljenost | 4,37[5] sv. l. |
| Absolutni izsev (MV) | 5,71[6] |
| Podrobnosti | |
| Alpha Centauri A | |
| Masa | 1,100[7] M☉ |
| Polmer | 1,2234±0,0053[8] R☉ |
| Izsev | 1,519[7] L☉ |
| Površinska težnost (log g) | 4,30[9] cgs |
| Temperatura | 5.790[7] K |
| Kovinskost [Fe/H] | 0,20[7] dex |
| Vrtenje | 22±5,9 dni[10] |
| Tirna hitrost(v sin i) | 2,7±0,7[10] km/s |
| Alpha Centauri B | |
| Masa | 0,907[7] M☉ |
| Polmer | 0,8632±0,0037[8] R☉ |
| Izsev | 0,5002[7] L☉ |
| Površinska težnost (log g) | 4,37[9] cgs |
| Temperatura | 5.260[7] K |
| Kovinskost | 0,23[7] |
| Vrtenje | 36[11] days |
| Tirna hitrost(v sin i) | 1,1±0,8[12] km/s |
| Starost | 5,3±0,3[13] Ga |
| Orbita[14] | |
| Primarna | A |
| Spremljevalka | B |
| Perioda (P) | 79,91±0,011 l |
| Glavna polos (a) | 17,57±0,022″ |
| Izsrednost tira (e) | 0,5179±0,00076 |
| Naklon tira (i) | 79,205±0,041° |
| Dolžina vozla (Ω) | 204,85±0,084° |
| Epoha periastrona (T) | 1875,66±0,012 |
| Argument periastrona (ω) (sekundarni) | 231,65±0,076° |
| Druge oznake | |
| 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 | |
| Sklici na podatkovne baze | |
| SIMBAD | AB |
| [1] | |
| [2] | |
| Exoplanet Archive | podatki |
| ARICNS | podatki |
| Extrasolar Planets Encyclopaedia | podatki |
Sistem Alfe Kentavra je nabližje Osončju in je oddaljen približno 1,3 parseka, oziroma 4,3 svetlobna leta.
Opombe
uredi- ↑ Proksima Kentavra je gravitacijsko veznana na sistem α Kentavra, a zaradi praktičnih in zgodovinskih razlogov je opisana v tem članku.
Sklici
uredi- ↑ 1,00 1,01 1,02 1,03 1,04 1,05 1,06 1,07 1,08 1,09 Van Leeuwen, F. (2007). »Validation of the new Hipparcos reduction«. Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ↑ 2,0 2,1 2,2 2,3 2,4 2,5 Ducati, J. R. (2002). »VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system«. CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
- ↑ 3,0 3,1 Torres, C. A. O.; Quast, G. R.; da Silva, L .; de la Reza, R.; Melo, C. H. F.; Sterzik, M. (2006). »Search for associations containing young stars (SACY)«. Astronomy and Astrophysics. 460 (3): 695–708. arXiv:astro-ph/0609258. Bibcode:2006A&A...460..695T. doi:10.1051/0004-6361:20065602. ISSN 0004-6361.
- ↑ 4,0 4,1 Valenti, Jeff A.; Fischer, Debra A. (2005). »Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs«. The Astrophysical Journal Supplement Series. 159 (1): 141–166. Bibcode:2005ApJS..159..141V. doi:10.1086/430500. ISSN 0067-0049.
- ↑ 5,0 5,1 Wilkinson, John (2012). »The Sun and Stars«. New Eyes on the Sun. Astronomers' Universe. str. 219–236. doi:10.1007/978-3-642-22839-1_10. ISBN 978-3-642-22838-4. ISSN 1614-659X.
- ↑ 6,0 6,1 P. A. Wiegert; M. J. Holman (1997). »The stability of planets in the Alpha Centauri system«. The Astronomical Journal. 113: 1445–1450. arXiv:astro-ph/9609106. Bibcode:1997AJ....113.1445W. doi:10.1086/118360.
- ↑ 7,0 7,1 7,2 7,3 7,4 7,5 7,6 7,7 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. arXiv:astro-ph/0206283. Bibcode:2002A&A...392L...9T. doi:10.1051/0004-6361:20021074.
- ↑ 8,0 8,1 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. arXiv:1610.06185. Bibcode:2017A&A...597A.137K. doi:10.1051/0004-6361/201629505.
- ↑ 9,0 9,1 Gilli G.; Israelian G.; Ecuvillon A.; Santos N. C.; Mayor M. (2006). »Abundances of Refractory Elements in the Atmospheres of Stars with Extrasolar Planets«. Astronomy and Astrophysics. 449 (2): 723–36. arXiv:astro-ph/0512219. Bibcode:2006A&A...449..723G. doi:10.1051/0004-6361:20053850. libcode 2005astro.ph.12219G.
- ↑ 10,0 10,1 Bazot, M.; in sod. (2007). »Asteroseismology of α Centauri A. Evidence of rotational splitting«. Astronomy and Astrophysics. 470 (1): 295–302. arXiv:0706.1682. Bibcode:2007A&A...470..295B. doi:10.1051/0004-6361:20065694.
- ↑ 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. arXiv:1009.1652. Bibcode:2010ApJ...722..343D. doi:10.1088/0004-637X/722/1/343.
- ↑ 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.
- ↑ 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. arXiv:1806.07567. Bibcode:2018ApJ...864...99J. doi:10.3847/1538-4357/aad464.
- ↑ Pourbaix, D.; in sod. (2002). »Constraining the difference in convective blueshift between the components of alpha Centauri with precise radial velocities«. Astronomy and Astrophysics. 386 (1): 280–85. arXiv:astro-ph/0202400. Bibcode:2002A&A...386..280P. doi:10.1051/0004-6361:20020287.