Gaan na inhoud

Diphda

Koördinate: Sky map 00h 43m 35.37090s, −17° 59′ 11.7827″
in Wikipedia, die vrye ensiklopedie
Diphda
Diphda se ligging (in die rooi sirkel).
Diphda se ligging (in die rooi sirkel).
Sterrebeeld Walvis
Bayer-naam β Cet (afkorting)
Spektraaltipe K0 III[1]
Soort Reusester
Waarnemingsdata (Epog J2000)
Regte klimming 00h 43m 35.37090s[2]
Deklinasie -17° 59′ 11.7827″[2]
Skynmagnitude (m) 2,02[3]
Absolute magnitude (M) -0,13[4]
B-V-kleurindeks  +1,01[3]
U-B-kleurindeks  +0,88[3]
Besonderhede
Massa (M☉) 2,8[5]
Radius (R☉) 16,78 ± 0,25[6]
Ligsterkte (L☉) 139,1 ± 7,0[6]
Ouderdom (jaar) > 1 miljard[7]
Temperatuur (K) 4 797[8]
Afstand (ligjaar) 96,3
Rotasiespoed (km/s) 18[9]
Metaalinhoud [Fe/H] -0,09 deks[8]
Eienskappe
Veranderlikheid Vermoed[10]
Ander name
Deneb Kaitos, Diphda, Difda al Thani, Rana Secunda, 16 Cet, BD–18°115, GCTP 134.00, Gj 31, HD 4128, HIP 3419, HR 188, SAO 147420.[11]
Portaal  Portaalicoon   Sterrekunde

Diphda (ook bekend as Beta Ceti of β Cet) is die helderste ster in die sterrebeeld Walvis (Cetus). Hoewel dit die Bayer-naam Beta Ceti het, is dit met ’n skynbare magnitude van 2,04 eintlik helderder as Alpha Ceti met sy magnitude van 2,54. Die oranjereus is maklik om uit te ken vanweë sy ligging in ’n andersins donker deel van die hemelruim. Volgens parallaksmetings is dit sowat 96,3 ligjare van die Son af.[2]

Eienskappe

[wysig | wysig bron]
Die oranjereus Beta Ceti (Chandra-X-straalsterrewag, Nasa).

Diphda het ’n sterreklassifikasie van K0 III,[1] hoewel dit in sommige bronne as G9,5 III geklassifiseer word,[5] wat daarop dui dit lê op die skeidingslyn van G- en K-tipe sterre. "III" dui aan dit is ’n reusester wat die waterstof in sy kern opgebruik en weg van die hoofreeks beweeg het.[5] Dit verbrand nou helium in sy kern.[12] Diphda sal langer as 100 miljoen jaar in dié fase bly.[7]

Die ster se oppervlaktemperatuur is sowat 4 797 K,[8] en dit gee dit die tipiese oranje kleur van ’n K-tipe ster.[13] Ondanks sy koeler temperatuur is dit omtrent 145 keer so helder as die Son,[14] want sy radius is 18 keer[6] groter. Sy massa is 2,8 keer die Son s'n.[5]

Die ster toon opvlammings, wat beteken die helderheid vergroot, oor tydperke van verskeie dae. In vergelyking daarmee toon die Son opvlammings van enkele ure.[12]

Diphda straal sowat 2 000 keer soveel X-strale as die Son uit, wat beteken dit kan deur die Chandra-X-straalsterrewag afgeneem word.[7]

Name

[wysig | wysig bron]

Die ster se Bayer-naam is "Beta Ceti" en sy Flamsteed-naam "16 Ceti". Die tradisionele name is "Diphda" en "Deneb Kaitos". Diphda is Arabies vir "padda", van die frase ضفدع الثاني aḍ-ḍifdaʿ aṯ-ṯānī; die "tweede padda" (die "eerste padda" is Fomalhaut). Deneb Kaitos kom van الذنب القيتوس الجنوب Al Dhanab al Ḳaiṭos al Janūbīyy, "die suidelike stert van Cetus".[15]

In 2016 het die Internasionale Astronomiese Unie se sternaamwerkgroep (WGSN) die naam "Diphda" vir die ster goedgekeur.[16]

Verwysings

[wysig | wysig bron]
  1. ↑ 1,0 1,1 Montes, D. et al. (November 2001), "Late-type members of young stellar kinematic groups – I. Single stars", Monthly Notices of the Royal Astronomical Society 328 (1): 45–63, doi:10.1046/j.1365-8711.2001.04781.x, Bibcode: 2001MNRAS.328...45M 
  2. ↑ 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. ↑ 3,0 3,1 3,2 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J 
  4. ↑ Elgarøy, Øystein; Engvold, Oddbjørn; Lund, Niels (March 1999), "The Wilson-Bappu effect of the MgII K line – dependence on stellar temperature, activity and metallicity", Astronomy and Astrophysics 343: 222–228, Bibcode: 1999A&A...343..222E 
  5. ↑ 5,0 5,1 5,2 5,3 (March 2005) "Emission measures for the single giant β Ceti". Proceedings of the 13th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, held 5-9 July, 2004 in Hamburg, Germany, European Space Agency. 
  6. ↑ 6,0 6,1 6,2 Berio, P. et al. (November 2011), "Chromosphere of K giant stars. Geometrical extent and spatial structure detection", Astronomy & Astrophysics 535: A59, doi:10.1051/0004-6361/201117479, Bibcode: 2011A&A...535A..59B 
  7. ↑ 7,0 7,1 7,2 "Beta Ceti: Giant Star's Corona Brightens with Age". Chandra Photo Album (in Engels). Harvard-Smithsonian Center for Astrophysics. 20 Februarie 2009. Geargiveer vanaf die oorspronklike op 5 Februarie 2020. Besoek op 28 Desember 2011.
  8. ↑ 8,0 8,1 8,2 Massarotti, Alessandro; et al. (Januarie 2008). "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity". The Astronomical Journal. 135 (1): 209–231. Bibcode:2008AJ....135..209M. doi:10.1088/0004-6256/135/1/209.
  9. ↑ "Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR (in Engels). Centre de Données astronomiques de Strasbourg. Geargiveer vanaf die oorspronklike op 23 Januarie 2018. Besoek op 30 September 2010.
  10. ↑ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/gcvs. Oorspronklik gepubliseer in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  11. ↑ "bet Cet -- Variable Star". SIMBAD (in Engels). Centre de Données astronomiques de Strasbourg. Geargiveer vanaf die oorspronklike op 16 Maart 2016. Besoek op 30 September 2010.
  12. ↑ 12,0 12,1 Ayres, Thomas R.; Osten, Rachel A.; Brown, Alexander (November 2001). "3 Ms in the Life of β Ceti: Sustained Flare Activity on a Clump Giant Detected by the Extreme Ultraviolet Explorer". The Astrophysical Journal. 562 (1): L83–L86. Bibcode:2001ApJ...562L..83A. doi:10.1086/337971.
  13. ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, archived from the original on 2012-03-10, https://www.webcitation.org/6630AbtJZ?url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, besoek op 2012-01-16 
  14. ↑ Kaler, James B. "DENEB KAITOS (Beta Ceti)" (in Engels). University of Illinois. Geargiveer vanaf die oorspronklike op 3 November 2019. Besoek op 30 September 2010.
  15. ↑ Allen, Richard H. (1963). Star Names: Their Lore and Meaning (Herdruk uitg.). New York: Dover Publications Inc. p. 163. ISBN 0-486-21079-0. Besoek op 12 Desember 2010.
  16. ↑ "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Besoek op 28 Julie 2016.

Eksterne skakels

[wysig | wysig bron]
Ontsluit van "https://af.wikipedia.org/w/index.php?title=Diphda&oldid=2434067"
pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy