Wikipedia:WikiProject WikiFundi Content/Eta Carinae

Eta Carinae
Eta Carinae
The Homunculus Nebula, surrounding Eta Carinae, imaged by WFPC2 at red and near-ultraviolet wavelengths
Credit: Jon Morse (University of Colorado) & NASA Hubble Space Telescope
Observation data
Epoch J2000      Equinox J2000
Constellation Carina
Right ascension 10h 45m 03.591s[1]
Declination −59° 41′ 04.26″[1]
Apparent magnitude (V) −1.0 to ~7.6[2]
Characteristics
Spectral type variable[3] + O[4][5]
Apparent magnitude (U) 6.37[6]
Apparent magnitude (B) 6.82[6]
Apparent magnitude (R) 4.90[6]
Apparent magnitude (J) 3.39[6]
Apparent magnitude (H) 2.51[6]
Apparent magnitude (K) 0.94[6]
U−B color index −0.45[6]
B−V color index +0.61[6]
Variable type LBV[7] & binary[8]
Astrometry
Radial velocity (Rv)−25.0[9] km/s
Proper motion (μ) RA: −7.6[1] mas/yr
Dec.: 1.0[1] mas/yr
Distance7,500 ly
(2,300[10] pc)
Absolute magnitude (MV)−8.6 (2012)[11]
Details
η Car A
Mass~100-200[12][13] M☉
Radius60-800[14] R☉
Luminosity5,000,000[4][5] L☉
Temperature9,400-35,200[4] K
Age<3[5] Myr
η Car B
Mass30-80[13] M☉
Radius14.3-23.6[13] R☉
Luminosity<1,000,000[4][5] L☉
Temperature37,200[4] K
Age<3[5] Myr
Orbit
Primaryη Car A
Companionη Car B
Period (P)2022.7±1.3 days[15]
(5.54 yr)
Semi-major axis (a)15.4[16] AU
Eccentricity (e)0.9[17]
Inclination (i)130–145[16]°
Periastron epoch (T)2009.03[13]
Other designations
Foramen,[18] Tseen She,[19] 231 G Carinae,[20] HR 4210, HD 93308, CD−59°2620, IRAS 10431-5925, GC 14799, AAVSO 1041–59
Database references
SIMBADdata

Eta Carinae (abbreviated to η Carinae or η Car), formerly known as Eta Argus, is a stellar system containing at least two stars with a combined luminosity over five million times that of the Sun, located around 7500 light-years (2300 parsecs) distant in the direction of the constellation Carina. First recorded as a 4th magnitude star, it brightened considerably over the period 1837 to 1856 in an event known as the Great Eruption. Eta Carinae became the second brightest star in the sky between 11 and 14 March 1843 before fading well below naked eye visibility. It has brightened consistently since about 1940, peaking above magnitude 4.5 in 2014. Eta Carinae is circumpolar south of latitude 30°S, so it is never visible north of latitude 30°N.

The two main stars of the Eta Carinae system have an eccentric orbit with a period of 5.54 years. The primary is a peculiar star similar to a luminous blue variable (LBV) that was initially 150-250 M☉ of which it has lost at least 30 M☉ already, and is expected to explode as a supernova in the astronomically near future. This is the only star known to produce ultraviolet laser emission. The secondary star is hot and also highly luminous, probably of spectral class O, around 30-80 times as massive as the Sun. The system is heavily obscured by the Homunculus Nebula, material ejected from the primary during the Great Eruption. It is a member of the Trumpler 16 open cluster within the much larger Carina Nebula. Although unrelated to the star or Nebula, the weak Eta Carinids meteor shower has a radiant very close to Eta Carinae.

  1. ^ a b c d Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H.
  2. ^ Cite error: The named reference frew was invoked but never defined (see the help page).
  3. ^ Skiff, B. A. (2014). "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009–2014)". VizieR On-line Data Catalog: B/Mk. Originally Published in: Lowell Observatory (October 2014). 1: 2023. Bibcode:2014yCat....1.2023S.
  4. ^ a b c d e Verner, E.; Bruhweiler, F.; Gull, T. (2005). "The Binarity of η Carinae Revealed from Photoionization Modeling of the Spectral Variability of the Weigelt Blobs B and D". The Astrophysical Journal. 624 (2): 973. arXiv:astro-ph/0502106. Bibcode:2005ApJ...624..973V. doi:10.1086/429400. S2CID 18166928.
  5. ^ a b c d e Mehner, Andrea; Davidson, Kris; Ferland, Gary J.; Humphreys, Roberta M. (2010). "High-excitation Emission Lines near Eta Carinae, and Its Likely Companion Star". The Astrophysical Journal. 710 (1): 729–742. arXiv:0912.1067. Bibcode:2010ApJ...710..729M. doi:10.1088/0004-637X/710/1/729. S2CID 5032987.
  6. ^ a b c d e f g h 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.
  7. ^ Cite error: The named reference impostors was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference damineli was invoked but never defined (see the help page).
  9. ^ Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Washington: 0. Bibcode:1953GCRV..C......0W.
  10. ^ Cite error: The named reference company was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference smithfrew was invoked but never defined (see the help page).
  12. ^ Clementel, N.; Madura, T. I.; Kruip, C. J. H.; Paardekooper, J.-P.; Gull, T. R. (2015). "3D radiative transfer simulations of Eta Carinae's inner colliding winds - I. Ionization structure of helium at apastron". Monthly Notices of the Royal Astronomical Society. 447 (3): 2445. arXiv:1412.7569. Bibcode:2015MNRAS.447.2445C. doi:10.1093/mnras/stu2614.
  13. ^ a b c d Kashi, A.; Soker, N. (2010). "Periastron Passage Triggering of the 19th Century Eruptions of Eta Carinae". The Astrophysical Journal. 723 (1): 602–611. arXiv:0912.1439. Bibcode:2010ApJ...723..602K. doi:10.1088/0004-637X/723/1/602. S2CID 118399302.
  14. ^ Gull, T. R.; Damineli, A. (2010). "JD13 – Eta Carinae in the Context of the Most Massive Stars". Proceedings of the International Astronomical Union. 5: 373–398. arXiv:0910.3158. Bibcode:2010HiA....15..373G. doi:10.1017/S1743921310009890. S2CID 1845338.
  15. ^ Damineli, A.; Hillier, D. J.; Corcoran, M. F.; Stahl, O.; Levenhagen, R. S.; Leister, N. V.; Groh, J. H.; Teodoro, M.; Albacete Colombo, J. F.; Gonzalez, F.; Arias, J.; Levato, H.; Grosso, M.; Morrell, N.; Gamen, R.; Wallerstein, G.; Niemela, V. (2008). "The periodicity of the η Carinae events". Monthly Notices of the Royal Astronomical Society. 384 (4): 1649. arXiv:0711.4250. Bibcode:2008MNRAS.384.1649D. doi:10.1111/j.1365-2966.2007.12815.x. S2CID 14624515.
  16. ^ a b Cite error: The named reference madura was invoked but never defined (see the help page).
  17. ^ Damineli, Augusto; Conti, Peter S.; Lopes, Dalton F. (1997). "Eta Carinae: A long period binary?". New Astronomy. 2 (2): 107. Bibcode:1997NewA....2..107D. doi:10.1016/S1384-1076(97)00008-0.
  18. ^ Will Gater; Anton Vamplew; Jacqueline Mitton (June 2010). The practical astronomer. Dorling Kindersley. ISBN 978-1-4053-5620-6.
  19. ^ Allen, Richard Hinckley (1963). Star Names: Their Lore and Meaning. Dover Publications. p. 73. ISBN 978-0-486-21079-7.
  20. ^ Gould, Benjamin Apthorp (1879). "Uranometria Argentina : Brillantez Y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : Con atlas". Resultados del Observatorio Nacional Argentino en Cordoba ; V. 1. 1. Bibcode:1879RNAO....1.....G.