Peacock
Peacock
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Peacock se ligging (in die rooi sirkel). | ||||
Sterrebeeld | Pou | |||
Bayer-naam | Alpha Pavonis | |||
Spektraaltipe | B3 V[1] | |||
Soort | Dubbelster | |||
Waarnemingsdata (Epog J2000) | ||||
Regte klimming | 20h 25m 38.85705s[2] | |||
Deklinasie | -56° 44′ 06.3230″[2] | |||
Skynmagnitude (m) | 1,94[3] | |||
Absolute magnitude (M) | -1,762[4] | |||
B-V-kleurindeks | -0,20[3] | |||
U-B-kleurindeks | -0,71[3] | |||
Besonderhede | ||||
Massa (M☉) | 5,91[5] | |||
Radius (R☉) | 4,83[6] | |||
Ligsterkte (L☉) | 2 200[6] | |||
Ouderdom (jaar) | 48 miljoen[5] | |||
Temperatuur (K) | 17 711[5] | |||
Afstand (ligjaar) | 179 | |||
Rotasiespoed (km/s) | 16[5] | |||
Ander name | ||||
CD-57° 9674, FK5 764, HD 193924, HIP 100751, HR 7790, SAO 246574[7] | ||||
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Peacock (ook bekend as Alpha Pavonis of α Pav) is ’n dubbelster in die suidelike sterrebeeld Pou (Pavo), naby sy grens met die Teleskoop.
Naam
[wysig | wysig bron]Die ster se Bayer-naam is "Alpha Pavonis". Die historiese naam, "Peacock" is in die laat 1930's deur Her Majesty's Nautical Almanac Office daaraan gegee tydens die samestelling van die Air Almanac, ’n navigasie-almanak vir die Britse lugmag (RAF). Van die 57 sterre wat in die nuwe almanak ingesluit is, het twee geen klassieke name gehad nie: Alpha Pavonis en Epsilon Carinae. Die RAF het daarop aangedring dat al die sterre name moet hê en nuwe name is dus geskep. Alpha Pavonis is "Peacock" genoem (pavo is Latyn en peacock Engels vir "pou") en Epsilon Carinae is "Avior" genoem.[8] In Julie 2016 het die Internasionale Astronomiese Unie se sternaamwerkgroep (WGSN)[9] die amptelike naam "Peacock" vir die ster goedgekeur.[10]
Eienskappe
[wysig | wysig bron]Met ’n skynbare magnitude van 1,94[3] is Peacock die helderste ster in die Pou. Volgens parallaksmetings is dit sowat 179 ligjare van die Son af.[2] Sy massa en radius is sowat ses keer dié van die Son, maar sy ligsterkte is 2 200 keer die Son s'n.[6] Die effektiewe temperatuur van sy fotosfeer is 17 700 K, wat die ster die tipiese blouwit kleur van B-tipe sterre gee.[11] Dit is van spektraaltipe B3 V,[1] dus ’n hoofreeksster, hoewel ouer studies dikwels daaraan die ligsterkteklas van ’n subreus gegee het.[12] Dit word as B2,5 IV geklassifiseer in die Bright Star Catalogue.[13]
Die stelsel is moontlik lid van die Tucana-Horologium-assosiasie van sterre wat saam deur die ruimte beweeg.[4] Die geraamde ouderdom van die assosiasie is 45 miljoen jaar.[4] Peacock het ’n uitsonderlike snelheid van 13 km s-1 relatief tot sy buursterre.[14]
Metgesel
[wysig | wysig bron]Drie sterre word genoem as metgeselle vir Alpha Pavonis: twee van die 9de magnitude by sowat 4 boogminute; en ’n F5-hoofreeksster van die 12de magnitude by sowat 1 boogminuut.[15][1] Die twee metgeselle van die 9de magnitude is net 17 boogsekondes van mekaar af.[15]
Alpha Pavonis A is ’n spektroskopiese dubbelster wat bestaan uit twee sterre wat elke 11,753 dae om mekaar wentel.[16] Die twee sterre is nog nie individueel waargeneem nie en daarom is min van die metgesel bekend, behalwe dat sy massa minstens 0,26 sonmassas is.[17]
Verwysings
[wysig | wysig bron]- ↑ 1,0 1,1 1,2 Gahm, G. F.; Ahlin, P.; Lindroos, K. P. (1983). "A study of visual double stars with early type primaries. I - Spectroscopic results". Astronomy and Astrophysics Supplement Series. 51: 143. Bibcode:1983A&AS...51..143G.
- ↑ 2,0 2,1 2,2 van Leeuwen, F. (November 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.
- ↑ 3,0 3,1 3,2 3,3 Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series 34: 1–49, Bibcode: 1978A&AS...34....1N
- ↑ 4,0 4,1 4,2 Bell, Cameron P. M.; Mamajek, Eric E.; Naylor, Tim (2015). "A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood". Monthly Notices of the Royal Astronomical Society. 454: 593. arXiv:1508.05955. Bibcode:2015MNRAS.454..593B. doi:10.1093/mnras/stv1981.
- ↑ 5,0 5,1 5,2 5,3 David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146.
- ↑ 6,0 6,1 6,2 Jerzykiewicz, M.; Molenda-Zakowicz, J. (September 2000), "Empirical Luminosities and Radii of Early-Type Stars after Hipparcos", Acta Astronomica 50: 369–380, Bibcode: 2000AcA....50..369J
- ↑ "PEACOCK -- Spectroscopic binary", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Alpha+Pavonis, besoek op 2011-12-23
- ↑ Sadler, D. H. (1993), A Personal History of H.M. Nautical Almanac Office, Edited and privately published by Wilkins, G. A., p. 48, archived from the original on 3 April 2012, https://web.archive.org/web/20120403214348/http://astro.ukho.gov.uk/nao/history/dhs_gaw/nao_perhist_0802_dhs.pdf, besoek op 21 Junie 2019
- ↑ "IAU Working Group on Star Names (WGSN)" (in Engels). Geargiveer vanaf die oorspronklike op 13 Mei 2020. Besoek op 22 Mei 2016.
- ↑ "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Besoek op 28 Julie 2016.
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, archived from the original on 10 Maart 2012, https://www.webcitation.org/6630AbtJZ?url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, besoek op 2012-01-16
- ↑ Skiff, B. A. (2014). "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009-2016)". VizieR On-line Data Catalog: B/mk. Originally published in: Lowell Observatory (October 2014). 1. Bibcode:2014yCat....1.2023S.
- ↑ Hoffleit, D.; Jaschek, C. (1991). The Bright star catalogue. New Haven: Yale University Observatory. Bibcode:1991bsc..book.....H.
- ↑ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (Januarie 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T
- ↑ 15,0 15,1 Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
- ↑ Vidal-Madjar, A. et al. (Augustus 1988), "Deuterium in early-type stars - The case of Alpha-Pavonis", Astronomy and Astrophysics 201 (2): 273–275, Bibcode: 1988A&A...201..273V
Eksterne skakels
[wysig | wysig bron]- Peacock - Jim Kaler's Stars
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