Alpha Sextantis
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]
Alpha Sextantis
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| Die ligging van Alpha Sextantis (in die rooi sirkel). | ||||
| Sterrebeeld | Sekstant | |||
| Spektraaltipe | A0 III[1] | |||
| Soort | Reusester | |||
| Waarnemingsdata (Epog J2000) | ||||
| Regte klimming | 10h 07m 56.29556s[2] | |||
| Deklinasie | -0° 22′ 17.8621″[2] | |||
| Skynmagnitude (m) | 4,49[3] | |||
| Absolute magnitude (M) | −0,29±0,21[4] | |||
| B-V-kleurindeks | -0,04[3] | |||
| U-B-kleurindeks | -0,07[3] | |||
| Besonderhede | ||||
| Massa (M☉) | 2,96±0,12[4] | |||
| Radius (R☉) | 4,5[5] | |||
| Ligsterkte (L☉) | 120[6] | |||
| Ouderdom (jaar) | 295[7] | |||
| Temperatuur (K) | 9 984[6] | |||
| Afstand (ligjaar) | 280 | |||
| Rotasiespoed (km/s) | 21[8] | |||
| Metaalinhoud [Fe/H] | −0,03±0,18[9] | |||
| Ander name | ||||
| 15 Sextantis, BD+00° 2615, FK5 2814, HD 87887, HIP 49641, HR 3981, SAO 137366[10] | ||||
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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
wysig- ↑ 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
wysig- Astronomy Knowledge Database
Hierdie artikel is vertaal uit die Engelse Wikipedia
