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 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 | |
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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) | ±0,76 −21,4[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 |
Rastojanje | 4.37[5] sg |
Apsolutna magnituda (MV) | 4.38[6] |
B | |
Radijalna brzina (Rv) | ±1,64 −18,6[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 |
Rastojanje | 4.37[5] sg |
Apsolutna magnituda (MV) | 5.71[6] |
Detalji | |
Alfa Kentauri A | |
Masa | 1.100[7] M☉ |
Poluprečnik | ±0,0053 1,2234[8] R☉ |
Luminoznost | 1.519[7] L☉ |
Površinska gravitacija (log g) | 4.30[9] cgs |
Temperatura | 5,790[7] K |
Metaličnost [Fe/H] | 0.20[7] dex |
Rotacija | ±5,9 d 22[10] |
Rotaciona brzina (v sin i) | ±0,7 2,7[10] km/s |
Alfa Kentauri B | |
Masa | 0.907[7] M☉ |
Poluprečnik | ±0,0037 0,8632[8] R☉ |
Luminoznost | 0.5002[7] L☉ |
Površinska gravitacija (log g) | 4.37[9] cgs |
Temperatura | 5,260[7] K |
Metaličnost | 0.23[7] |
Rotacija | 36[11] days |
Rotaciona brzina (v sin i) | ±0,8 1,1[12] km/s |
Starost | ±0,3 5,3[13] Gyr |
Orbita[14] | |
Primarna | A |
Kompanjon | B |
Period (P) | ±0,011 79,91g |
Velika poluosa (a) | ±0,022″ 17,57 |
Ekscentricitet (e) | ±0,00076 0,5179 |
Inklinacija (i) | ±0,041° 79,205 |
Longituda uzlaznog čvora (Ω) | ±0,084° 204,85 |
Apsidna epoha (T) | 875,66±0,012 1 |
Argument perihela (ω) (sekundarni) | ±0,076° 231,65 |
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 | |
Referentne baze podataka | |
SIMBAD | AB |
A | |
B | |
Ekstrasolarna arhiva | data |
ARICNS | data |
Enciklopedija ekstrasolarnih planeta | data |
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
urediIzvor | Paralaksa (mas) | Rastojanje (pc) | Rastojanje (ly) | Rastojanje (Pm) | Reference |
---|---|---|---|---|---|
Henderson (1839) | ±110 1160 | +0,09 −0,07 0,86 |
2.57 ± 0.53 | +2,8 −2,3 26,6 |
[15] |
Henderson (1842) | ±64 912,8 | 1.03 ± 0.15 | 3.34 ± 0.5 | +2,5 −2,2 33,8 |
[16] |
Maklir (1851) | ±34 918,7 | ±0,04 1,09 | +0,14 −0,13 3,55 |
32.4 ± 2.5 | [17] |
Moesta (1868) | ±68 880 | +0,10 −0,08 1,14 |
+0,31 −0,27 3,71 |
+2,9 −2,5 35,1 |
[18] |
Gil & Elkin (1885) | ±10 750 | ±0,018 1,333 | ±0,06 4,35 | +0,6 −0,5 41,1 |
[19] |
Roberts (1895) | ±50 710 | 1.32 ± 0.2 | 4.29 ± 0.65 | +3,3 −2,9 43,5 |
[20] |
Vuli et al. (1970) | ±7 743 | ±0,013 1,346 | ±0,04 4,39 | ±0,4 41,5 | [21] |
Glis & Jahreib (1991) | ±4,7 749,0 | ±0,008 1,335 | ±0,027 4,355 | ±0,26 41,20 | [22] |
van Altena et al. (1995) | ±5,4 749,9 | ±0,010 1,334 | +0,032 −0,031 4,349 |
+0,30 −0,29 41,15 |
[23] |
Periman et al. (1997) (A and B) | ±1,40 742,12 | ±0,0025 1,3475 | ±0,008 4,395 | ±0,08 41,58 | [24] |
Sederhjelm (1999) | ±1,2 747,1 | +0,0022 −0,0021 1,3385 |
±0,007 4,366 | ±0,07 41,30 | [28] |
van Liuven (2007) (A) | ±4,11 754,81 | ±0,007 1,325 | +0,024 −0,023 4,321 |
±0,22 40,88 | [29] |
van Liuven (2007) (B) | ±25,90 796,92 | ±0,04 1,25 | +0,14 −0,13 4,09 |
37.5 ± 2.5 | [30] |
RECONS TOP100 (2012) | ±1,17 747,23[note 2] | ±0,0021 1,3383 | ±0,007 4,365 | ±0,06 41,29 | [31] |
Napomene
uredi- ^ 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.
- ^ Weighted parallax based on parallaxes from van Altena et al. (1995) and Söderhjelm (1999).
Reference
uredi- ^ a b v g d đ e ž z i Van Leeuwen, F. (2007). „Validation of the new Hipparcos reduction”. Astronomy and Astrophysics. 474 (2): 653—664. Bibcode:2007A&A...474..653V. arXiv:0708.1752 . doi:10.1051/0004-6361:20078357.
- ^ a b v g d đ 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.
- ^ a b 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. Bibcode:2006A&A...460..695T. ISSN 0004-6361. arXiv:astro-ph/0609258 . doi:10.1051/0004-6361:20065602.
- ^ a b 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. ISSN 0067-0049. doi:10.1086/430500 .
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ a b 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. Bibcode:2006A&A...449..723G. arXiv:astro-ph/0512219 . doi:10.1051/0004-6361:20053850. libcode 2005astro.ph.12219G.
- ^ 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.
- ^ 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.
- ^ 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. Bibcode:2018ApJ...864...99J. arXiv:1806.07567 . doi:10.3847/1538-4357/aad464.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Gliese, W.; Jahreiß, H. (1991). „Gl 559”. Preliminary Version of the Third Catalogue of Nearby Stars. Astronomische Rechen-Institut. Pristupljeno 9. 5. 2014.
- ^ 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.
- ^ Perryman; et al. (1997). „HIP 71683”. The Hipparcos and Tycho Catalogues. Pristupljeno 9. 5. 2014.
- ^ Perryman; et al. (1997). „HIP 71683”. The Hipparcos and Tycho Catalogues. Pristupljeno 9. 5. 2014.
- ^ Perryman; et al. (1997). „HIP 71681”. The Hipparcos and Tycho Catalogues. Pristupljeno 9. 5. 2014.
- ^ Perryman; et al. (1997). „HIP 71681”. The Hipparcos and Tycho Catalogues. Pristupljeno 9. 5. 2014.
- ^ Söderhjelm, Staffan (1999). „HIP 71683”. Visual binary orbits and masses post Hipparcos. Pristupljeno 9. 5. 2014.
- ^ van Leeuwen, Floor (2007). „HIP 71683”. Validation of the new Hipparcos reduction.
- ^ van Leeuwen, Floor (2007). „HIP 71681”. Validation of the new Hipparcos reduction.
- ^ „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- SIMBAD observational data
- Sixth Catalogue of Orbits of Visual Binary Stars U.S.N.O.
- The Imperial Star – Alpha Centauri
- Alpha Centauri – A Voyage to Alpha Centauri
- Immediate History of Alpha Centauri
- eSky : Alpha Centauri
Hipotetične planete ili eksploracija
uredi- „A Family Portrait of the Alpha Centauri System”. SpaceRef.com: 5. 2003. Bibcode:2003eso..pres....5. Pristupljeno 21. 3. 2003.[mrtva veza]
- Alpha Centauri System
- O Sistema Alpha Centauri (Portuguese) Архивирано на сајту Wayback Machine (3. март 2016)
- Alpha Centauri – Associação de Astronomia (Portuguese)
- Thompson, Andrea (7. 3. 2008). „Nearest Star System Might Harbor Earth Twin”. SPACE.com. Arhivirano iz originala 2. 6. 2008. g. Pristupljeno 17. 7. 2008.