Nu Octantis

in Wikipedia, die vrye ensiklopedie
(Aangestuur vanaf HD 205478)
Nu Octantis
Die ligging van Nu Octantis (in die rooi sirkel).
Die ligging van Nu Octantis (in die rooi sirkel).
Sterrebeeld Oktant
Spektraaltipe K1 III[1]
Soort Dubbelster
Waarnemingsdata (Epog J2000)
Regte klimming 21h 41m 28.64977s[2]
Deklinasie -77° 23′ 24.1563″[2]
Skynmagnitude (m) 3,73[3]
Absolute magnitude (M) 2,1[3]
+2,02[4]
B-V-kleurindeks  +1.00[5]
U-B-kleurindeks  +0,89[5]
Besonderhede
Massa (M) 1,04[6]
1,61 / 0,585[4]
Radius (R) 5,9[6]
5,81 ± 0,12[4]
Ligsterkte (L) 17,53[3]
Ouderdom (jaar) ~2,5-3 miljard[4]
Temperatuur (K) 4 860 ± 40[7]
Afstand (ligjaar) 69,1
Rotasiespoed (km/s) 2[4]
Metaalinhoud [Fe/H] 0,18 ± 0,04[4]
Ander name
CD-77 1079, CCDM J21415-7723A, FK5 810, GC 30289, GJ 9744, HIP 107089, HR 8254, HD 205478, SAO 257948, WDS J21415-7723A
Portaal  Portaalicoon   Sterrekunde

Nu Octantis (afgekort as ν Oct) is ’n spektroskopiese dubbelster[8] in die sterrebeeld Oktant met ’n wentelperiode van sowat 2,9 jaar.[7] Met sy skynbare magnitude van 3,73[3] is dit die helderste ster in die sterrebeeld. Dit is sowat 69,1 ligjare van die Son af.[2] Die primêre ster is ’n oranje reusester van spektraaltipe K1 III,[1] en is dus ’n ster wat die waterstof in sy kern opgebruik en uitgesit het. Die sekondêre ster is waarskynlik ’n rooidwerg met ’n lae massa.[4]

In 2009 is voorgestel die stelsel het ’n eksoplaneet, geskoei op versteurings in die wentelperiode.[7] Die versteurings kan egter daaraan toegeskryf word dat die sekondêre ster self ’n dubbelster is,[9] aangesien die vorming van ’n planeet in so ’n stelsel moeilik sal wees vanweë dinamiese versteurings.[10]

Verwysings[wysig | wysig bron]

  1. 1,0 1,1 Gray, R. O.; et al. (Julie 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637.
  2. 2,0 2,1 2,2 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier-katalogus
  3. 3,0 3,1 3,2 3,3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. Vizier-katalogus
  4. 4,0 4,1 4,2 4,3 4,4 4,5 4,6 Ramm, D. J.; et al. (2016). "The conjectured S-type retrograde planet in ν Octantis: more evidence including four years of iodine-cell radial velocities". Monthly Notices of the Royal Astronomical Society. 460 (4): 3706–3719. arXiv:1605.06720. Bibcode:2016MNRAS.460.3706R. doi:10.1093/mnras/stw1106.
  5. 5,0 5,1 Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42: 443. Bibcode:2014JAVSO..42..443M.Vizier-katalogus
  6. 6,0 6,1 Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. Vizier-katalogus
  7. 7,0 7,1 7,2 Ramm, D. J.; Pourbaix, D.; Hearnshaw, J. B.; Komonjinda, S. (April 2009). "Spectroscopic orbits for K giants β Reticuli and ν Octantis: what is causing a low-amplitude radial velocity resonant perturbation in ν Oct?". Monthly Notices of the Royal Astronomical Society. 394 (3): 1695–1710. Bibcode:2009MNRAS.394.1695R. doi:10.1111/j.1365-2966.2009.14459.x.
  8. Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x.
  9. Morais, M. H. M.; Correia, A. C. M. (Februarie 2012). "Precession due to a close binary system: an alternative explanation for ν-Octantis?". Monthly Notices of the Royal Astronomical Society. 419 (4): 3447–3456. arXiv:1110.3176. Bibcode:2012MNRAS.419.3447M. doi:10.1111/j.1365-2966.2011.19986.x.
  10. Gozdziewski, K.; Slonina, M.; Migaszewski, C.; Rozenkiewicz, A. (Maart 2013). "Testing a hypothesis of the ν Octantis planetary system". Monthly Notices of the Royal Astronomical Society. 430 (1): 533–545. arXiv:1205.1341. Bibcode:2013MNRAS.430..533G. doi:10.1093/mnras/sts652.

Eksterne skakels[wysig | wysig bron]