Eta Carinae and the Supernova Impostors pp 221-247

Part of the Astrophysics and Space Science Library book series (ASSL, volume 384)

Eta Carinae and the Luminous Blue Variables

Abstract

We evaluate the place of Eta Carinae (η Car) among the class of luminous blue variables (LBVs) and show that the LBV phenomenon is not restricted to extremely luminous objects like η Car, but extends luminosities as low as log (L ∕ L) ∼ 5.4 – corresponding to initial masses ∼ 25 M, and final masses as low as ∼ 10–15 M. We present a census of S Doradus variability, and discuss basic LBV properties, their mass-loss behavior, and whether at maximum light they form pseudo-photospheres. We suggest that those objects that exhibit giant η Car-type eruptions are most likely related to the more common type of S Doradus variability. Alternative atmospheric models as well as sub-photospheric models for the instability are presented, but the true nature of the LBV phenomenon remains as yet elusive. We end with a discussion of the evolutionary status of LBVs – highlighting recent indications that some LBVs may be in a direct pre-supernova state, in contradiction to the standard paradigm for massive star evolution.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    D.C. Abbott, L.B. Lucy, Multiline transfer and the dynamics of stellar winds. ApJ. 288, 679–693 (1985)ADSCrossRefGoogle Scholar
  2. 2.
    I. Appenzeller, Mass loss rates for vibrationally unstable very massive main-sequence stars. A&A. 9, 216–220 (1970)ADSGoogle Scholar
  3. 3.
    I. Appenzeller, Instability in massive stars – an overview. in Proceedings of the IAUS, vol. 116 (D. Reidel, Dordrecht, 1986), pp. 139–148Google Scholar
  4. 4.
    I. Appenzeller, The role of radiation pressure in LBV atmospheres, in Proceedings of the IAUC, ed. by K. Davidson, A.F.P. Moffat, H. Lamersvol, vol. 113 (Kluwer, Dordrecht, 1989), pp. 195–202Google Scholar
  5. 5.
    P. Benaglia, J.S. Vink, J. Marti, J. Maiz Apellaniz, B. Koribalski, P.A. Crowther, Testing the predicted mass-loss bi-stability jump at radio wavelengths. A&A. 467, 1265–1274 (2007)ADSCrossRefGoogle Scholar
  6. 6.
    E. Berger, A.M. Soderberg, R.A. Chevalier et al., An intermediate luminosity transient in NGC 300: the eruption of a dust-enshrouded massive star. ApJ. 699, 1850 (2009)ADSCrossRefGoogle Scholar
  7. 7.
    H.E. Bond, L.R. Bedin, A.Z. Bonanos et al., The 2008 luminous optical transient in the nearby Galaxy NGC 300. ApJ. 695, 154 (2009)ADSCrossRefGoogle Scholar
  8. 8.
    M.T. Botticella, A. Pastorello, S.J. Smartt et al., SN 2008S: an electron-capture SN from a super-AGB progenitor? MNRAS. 398, 1041 (2009)ADSCrossRefGoogle Scholar
  9. 9.
    C. Buemi, E. Distefano, P. Leto et al., Photometric monitoring of Luminous Blue Variables. BSRSL 80, 335 (2011)ADSGoogle Scholar
  10. 10.
    M. Cantiello, N. Langer, I. Brott et al., Sub-surface convection zones in hot massive stars and their observable consequences. A&A. 499, 279–290 (2009)ADSCrossRefGoogle Scholar
  11. 11.
    J.I. Castor, D.C. Abbott, R.I. Klein, Radiation-driven winds in of stars. ApJ. 195, 157–174 (1975)Google Scholar
  12. 12.
    J.S. Clark, V.M. Larionov, A. Arkharov, On the population of galactic Luminous Blue Variables. A&A. 435, 239–246 (2005)ADSCrossRefGoogle Scholar
  13. 13.
    J.S. Clark, P.A. Crowther, V.M. Larionov et al., Bolometric luminosity variations in the luminous blue variable AFGL2298. A&A. 507, 1555–1565 (2009)ADSCrossRefGoogle Scholar
  14. 14.
    P. Cox, P.G. Mezger, A. Sievers et al., Millimeter emission of eta Carinae and its surroundings. A&A. 297, 168–174 (1995)ADSGoogle Scholar
  15. 15.
    P.A. Crowther, D.J. Lennon, N.R. Walborn, Physical parameters and wind properties of galactic early B supergiants. A&A. 446, 279–293 (2006)ADSCrossRefGoogle Scholar
  16. 16.
    A. Damineli, The 5.52 year cycle of Eta Carinae. ApJ. 460, L49–L52 (1996)Google Scholar
  17. 17.
    K. Davidson, On the nature of Eta Carinae. MNRAS. 154, 415–427 (1971)ADSGoogle Scholar
  18. 18.
    K. Davidson, The relation between apparent temperature and mass-loss rate in hypergiant eruptions. ApJ. 317, 760–764 (1987)ADSCrossRefGoogle Scholar
  19. 19.
    K. Davidson, N.R. Walborn, T.R. Gull, The remarkable spectrum of some material ejected by Eta Carinae. ApJ. 254, L47–L51 (1982)ADSCrossRefGoogle Scholar
  20. 20.
    K. Davidson, D. Ebbets, G. Weigelt, HST/FOS spectroscopy of ETA Carinae: the star itself, and ejecta within 0.3 arcsec. AJ. 109, 1784–1796 (1995)Google Scholar
  21. 21.
    B. Davies, R.D. Oudmaijer, J.S. Vink, Asphericity and clumpiness in the winds of Luminous Blue Variables. A&A. 439, 1107–1125 (2005)ADSCrossRefGoogle Scholar
  22. 22.
    B. Davies, J.S. Vink, R.D. Oudmaijer, Modelling the clumping-induced polarimetric variability of hot star winds. A&A. 469, 1045–1056 (2007)ADSCrossRefGoogle Scholar
  23. 23.
    B. Davies, R.D. Oudmaijer, K.C. Sahu, Integral-field spectroscopy of the post-red supergiant IRC + 10420: evidence for an axisymmetric wind. ApJ. 671, 2059–2067 (2007)ADSCrossRefGoogle Scholar
  24. 24.
    M. de Groot, C. Sterken, A.M. van Genderen, Cyclicities in the light variations of S Doradus stars III. P Cygni. A&A. 376, 224–231 (2001)CrossRefGoogle Scholar
  25. 25.
    C. de Jager, The stability limit of hypergiant photospheres. A&A. 138, 246–252 (1984)ADSGoogle Scholar
  26. 26.
    C. de Jager, The yellow hypergiants. A&ARv. 8, 145–180 (1998)Google Scholar
  27. 27.
    A. de Koter, H.J.G.L.M. Lamers, W. Schmutz, Variability of Luminous Blue Variables. II. Parameter study of the typical LBV variations. A&A. 306, 501–518 (1996)Google Scholar
  28. 28.
    W.J. de Wit, R.D. Oudmaijer, M.A.T. Groenewegen, M.G. Hoare, F. Malbet, Resolving the ionized wind of the post-red supergiant IRC +10 420 with VLTI/AMBER. A&A. 480, 149–155 (2008)ADSCrossRefGoogle Scholar
  29. 29.
    V.V. Dwarkadas, On Luminous Blue Variables as the progenitors of core-collapse supernovae, especially type IIn supernovae. MNRAS. 412, 1639–1649 (2011)ADSCrossRefGoogle Scholar
  30. 30.
    R.J. Foley, N. Smith, M. Ganeshalingam et al., SN 2006jc: a wolf-rayet star exploding in a dense he-rich circumstellar medium. ApJ. 657, L105–L108 (2007)ADSCrossRefGoogle Scholar
  31. 31.
    A. Gal-Yam, D.C. Leonard, D.B. Fox et al., On the progenitor of SN 2005gl and the nature of type IIn supernovae. ApJ. 656, 372–381 (2007)ADSCrossRefGoogle Scholar
  32. 32.
    G. Garcia-Segura, N. Langer, M.-M. Mac Low, The dynamical evolution of circumstellar gas around massive stars. I. The impact of the time sequence Ostar – LBV – WR star. A&A. 305, 229–244 (1996)Google Scholar
  33. 33.
    W. Glatzel, M. Kiriakidis, Stability of massive stars and the Humphreys-Davidson limit. MNRAS 263, 375–384 (1993)ADSGoogle Scholar
  34. 34.
    G. Grafener, S.P. Owocki, J.S. Vink, Stellar envelope inflation near the Eddington limit. Implications for the radii of Wolf-Rayet stars and luminous blue variables. A&A. 538, idA40 (2012)Google Scholar
  35. 35.
    J.H. Groh, J.S. Vink, The bi-stability jump as the origin for multiple P-Cygni absorption components in Luminous Blue Variables. A&AL. 513, 10–13 (2011)CrossRefGoogle Scholar
  36. 36.
    J.H. Groh, D.J. Hillier, A. Damineli, AG Carinae: a luminous blue variable with a high rotational velocity. ApJ. 638, L33–L36 (2006)ADSCrossRefGoogle Scholar
  37. 37.
    J.H. Groh, D.J. Hillier, A. Damineli, P.A. Whitelock, F. Marang, C. Rossi, On the nature of the prototype luminous blue variable AG Carinae. I. Fundamental parameters during visual minimum phases and changes in the bolometric luminosity during the S-Dor cycle. ApJ. 698, 1698–1720 (2009)Google Scholar
  38. 38.
    J.H. Groh, D.J. Hillier, A. Damineli et al., Bona fide, strong-variable galactic luminous blue variable stars are fast rotators: detection of a high rotational velocity in HR Carinae. ApJL. 705, L25–L30 (2009)ADSCrossRefGoogle Scholar
  39. 39.
    J.H. Guo, Y. Li, Estimating the structure and geometry of winds from Luminous Blue Variables via fitting the continuum energy distributions. ApJ. 659, 1563–1575 (2007)ADSCrossRefGoogle Scholar
  40. 40.
    V.V. Gvaramadze, A.Y. Kniazev, S. Fabrika et al., MN112: a new Galactic candidate Luminous Blue Variable. MNRAS. 405, 520–524 (2010)ADSGoogle Scholar
  41. 41.
    W.-R. Hamann, A. Feldmeier, L.M. Oskinova, Clumping in Hot-Star Winds: Proceedings of an International Workshop held in Potsdam, Germany, 18–22 June 2007, Potsdam Universitätsverlag, Potsdam, 2008Google Scholar
  42. 42.
    T.J. Harries, D.J. Hillier, I.D. Howarth, A spectropolarimetric survey of northern hemisphere Wolf-Rayet stars. MNRAS. 296, 1072–1088 (1998)ADSCrossRefGoogle Scholar
  43. 43.
    T.J. Harries, I.D. Howarth, C.J. Evans, Spectropolarimetry of O supergiants. MNRAS. 337, 341–355 (2002)CrossRefGoogle Scholar
  44. 44.
    A. Herrero, M. Garcia, K. Uytterhoeven et al., The nature of V39: an LBV candidate or LBV impostor in the very low metallicity galaxy IC 1613? A&A. 513, 70 (2010)ADSCrossRefGoogle Scholar
  45. 45.
    D.J. Hillier, D.L. Miller, The treatment of non-LTE line blanketing in spherically expanding outflows. ApJ. 496, 407 (1998)ADSCrossRefGoogle Scholar
  46. 46.
    D.J. Hillier, P.A. Crowther, F. Najarro, A.W. Fullerton, An optical and near-IR spectroscopic study of the extreme P Cygni-type supergiant HDE 316285. A&A. 340, 483–496 (1998)ADSGoogle Scholar
  47. 47.
    D.J. Hillier, K. Davidson, K. Ishibashi, T. Gull, On the nature of the central source in η Carinae. ApJ. 553, 837–860 (2001)ADSCrossRefGoogle Scholar
  48. 48.
    E. Hubble, A. Sandage, The brightest variable stars in extragalactic nebulae. I. M31 and M33. ApJ. 118, 353–361 (1953)Google Scholar
  49. 49.
    R.M. Humphreys, Studies of luminous stars in nearby galaxies I supergiants and O stars in the Milky Way. ApJ. Suppl. 38, 309 (1978)ADSCrossRefGoogle Scholar
  50. 50.
    R.M. Humphreys, K. Davidson, Studies of luminous stars in nearby galaxies. III – comments on the evolution of the most massive stars in the Milky Way and the Large Magellanic Cloud. ApJ. 232, 409–420 (1979)Google Scholar
  51. 51.
    R.M. Humphreys, K. Davidson, The most luminous stars. Science 223, 243–249 (1984)Google Scholar
  52. 52.
    R.M. Humphreys, K. Davidson, The Luminous Blue Variables: astrophysical geysers. PASP. 106, 1025–1051 (1994)ADSCrossRefGoogle Scholar
  53. 53.
    R.M. Humphreys, N. Smith, K. Davidson, et al., HST and infrared images of the circumstellar environment of the cool hypergiant IRC + 10420. AJ. 114, 2778 (1997)ADSCrossRefGoogle Scholar
  54. 54.
    R.M. Humphreys, K. Davidson, N. Smith, Eta Carinae’s second eruption and the light curves of the eta Carinae variables. PASP. 111, 1124–1131 (1999)ADSCrossRefGoogle Scholar
  55. 55.
    R.M. Humphreys, K. Davidson, N. Smith, Crossing the yellow void: spatially resolved spectroscopy of the post-red supergiant IRC + 10420 and its circumstellar ejecta. AJ. 124, 1026–1044 (2002)ADSCrossRefGoogle Scholar
  56. 56.
    R.M. Humphreys, H. E. Bond, L. Bedin, A.Z. Bonanos, K. Davidson, B. L. A. G. Monard, J. Prieto, F. M. Walter, The photometric and spectral evolution of the 2008 luminous optical transient in NGC 300. ApJ. 743, id 118 (2011)Google Scholar
  57. 57.
    J.B. Hutchings, Stellar winds from hot supergiants. ApJ. 203, 438 (1976)Google Scholar
  58. 58.
    Y.I. Izotov, T.X. Thuan, Luminous blue variable stars in the two extremely metal-deficient blue compact dwarf galaxies DDO 68 and PHL 293B. ApJ. 690, 1797–1806 (2009)ADSCrossRefGoogle Scholar
  59. 59.
    T.J. Jones, R.M. Humphreys, R.D. Gehrz et al., IRC + 10420 – A cool hypergiant near the top of the H-R diagram. ApJ. 411, 323–335 (1993)ADSCrossRefGoogle Scholar
  60. 60.
    A. Kashi, An indication for the binarity of P Cygni from its seventeenth century eruption, MNRAS. in press, http://arxiv.org/abs/0912.3998 (2010)
  61. 61.
    R. Kotak, J.S. Vink, Luminous Blue Variables as the progenitors of supernovae with quasi-periodic radio modulations. A&A. 460, L5–L8 (2006)ADSCrossRefGoogle Scholar
  62. 62.
    H.J.G.L.M. Lamers, P Cygni type stars – evolution and physical processes. in Proceedings of the IAUS, vol. 116 (D. Reidel, Dordrecht, 1986), pp. 157–178Google Scholar
  63. 63.
    H.J.G.L.M. Lamers, J.P. Cassinelli, Introduction to Stellar Winds (Cambridge University Press, Cambridge, 1999)Google Scholar
  64. 64.
    H.J.G.L.M. Lamers, E.L. Fitzpatrick, The relationship between the Eddington limit, the observed upper luminosity limit for massive stars, and the Luminous Blue Variables. ApJ. 324, 279–287 (1988)Google Scholar
  65. 65.
    H.J.G.L.M. Lamers, A.W.A. Pauldrach, The formation of outflowing disks around early-type stars by bi-stable radiation-driven winds. A&A. 244, L5–L8 (1991)Google Scholar
  66. 66.
    H.J.G.L.M. Lamers, P. Korevaar, A. Cassatella, The ejection of shells in the stellar wind of the hypergiant P Cygni (B1 Ia/+/). A&A. 149, 29–40 (1985)Google Scholar
  67. 67.
    H.J.G.L.M. Lamers, Th.P.Snow, D.M. Lindholm, Terminal velocities and the bistability of stellar winds. ApJ. 455, 269 (1995)Google Scholar
  68. 68.
    H.J.G.L.M. Lamers, F.-J. Zickgraf, D. de Winter, L. Houziaux, J. Zorec, An improved classification of B[e]-type stars. A&A. 340, 117–128 (1998)Google Scholar
  69. 69.
    N. Langer, The Eddington limit in rotating massive stars. ASPC. 120, 83 (1997)ADSGoogle Scholar
  70. 70.
    N. Langer, W-R. Hamann, M. Lennon et al., Towards an understanding of very massive stars. A new evolutionary scenario relating O stars, LBVs and Wolf-Rayet stars. A&A. 290, 819–833 (1994)Google Scholar
  71. 71.
    K. Lefever, J. Puls, C. Aerts, Statistical properties of a sample of periodically variable B-type supergiants. Evidence for opacity-driven gravity-mode oscillations. A&A. 463, 1093–1109 (2007)Google Scholar
  72. 72.
    C. Leitherer, Mass loss from LBVs: observational constraints. ASPC. 120, 58–65 (1997)ADSGoogle Scholar
  73. 73.
    C. Leitherer, W. Schmutz, D.C. Abbott, W.-R Hamann, U. Wessolowski, Atmospheric models for Luminous Blue Variables. ApJ. 346, 919–931 (1989)Google Scholar
  74. 74.
    D.J. Lennon, D. Wobig, R.-P. Kudritzki, O. Stahl, The atmospheric composition, extinction and luminosity of the LBV star R71. SSRv. 66, 207 (1993)ADSGoogle Scholar
  75. 75.
    L.B. Lucy, An analysis of the variable radial velocity of alpha Cygni. ApJ. 206, 499–508 (1976)ADSCrossRefGoogle Scholar
  76. 76.
    L.B. Lucy, P.M. Solomon, Mass loss by hot stars. ApJ. 159, 879–893 (1970)Google Scholar
  77. 77.
    A. Maeder, Evolution of chemical abundances in massive stars. I – OB stars, Hubble-Sandage variables and Wolf-Rayet stars – Changes at stellar surfaces and galactic enrichment by stellar winds. II – Abundance anomalies in Wolf-Rayet stars in relation with cosmic rays and 22/Ne in meteorites. A&A. 120, 113–135 (1983)Google Scholar
  78. 78.
    N. Markova, J. Puls, Bright OB stars in the galaxy. IV. Stellar and wind parameters of early to late B supergiants. A&A. 478, 823–842 (2008)Google Scholar
  79. 79.
    N. Markova, N. Morrison, I. Kolka, H. Markov, P Cygni in a short S Doradus phase. Spectroscopic and photometric evidences. A&A. 376, 898–906 (2001)Google Scholar
  80. 80.
    F. Martins, S. Trippe, T. Paumard et al., GCIRS 16SW: a massive eclipsing binary in the galactic center. ApJ. 649, L103–L106 (2006)ADSCrossRefGoogle Scholar
  81. 81.
    O. Maryeva, P. Abolmasov, Modeling the optical spectrum of Romano’s star. MNRAS. submitted (arXiv:1109.0443), (2011)Google Scholar
  82. 82.
    P. Massey, R.T. McNeill, K.A.G. Olsen et al., A survey of local group galaxies currently forming stars. III. A search for Luminous Blue Variables and other H emission-line stars. AJ. 134, 2474–2503 (2007)Google Scholar
  83. 83.
    J.C. Mauerhan, M.R. Morris, A. Cotera et al., Discovery of a luminous blue variable with an ejection nebula near the quintuplet cluster. ApJ. 713, 33 (2010)ADSCrossRefGoogle Scholar
  84. 84.
    G. Meynet, A. Maeder, Stellar evolution with rotation. XI. Wolf-Rayet star populations at different metallicities. A&A. 429, 581–598 (2005)Google Scholar
  85. 85.
    P.E. Müller, J.S. Vink, A consistent solution for the velocity field and mass-loss rate of massive stars. A&A. 492, 493–509 (2008)ADSMATHCrossRefGoogle Scholar
  86. 86.
    F. Najarro, D.J. Hillier, O. Stahl, A spectroscopic investigation of P Cygni. I. H and HeI lines. A&A. 326, 1117–1134 (1997)ADSGoogle Scholar
  87. 87.
    K.H. Nordsieck, J. Wisniewski, B.L. Babler et al., Ultraviolet and visible spectropolarimetric variability in P Cygni. ASPC. 233, 261–274 (2001)ADSGoogle Scholar
  88. 88.
    A. Nota, M. Livio, M. Clampin, R. Schulte-Ladbeck, Nebulae around Luminous Blue Variables: a unified picture. ApJ. 448, 788–796 (1995)ADSCrossRefGoogle Scholar
  89. 89.
    R.D. Oudmaijer, M.A.T. Groenewegen, H.E. Matthews, J.A.D.L. Blommaert, K.C. Sahu, The spectral energy distribution and mass-loss history of IRC + 10420. MNRAS. 280, 1062–1070 (1996)ADSGoogle Scholar
  90. 90.
    R.D. Oudmaijer, B. Davies, W.-J. de Wit, M. Patel, Post-red supergiants, in ASP Conf. Series, vol. 412, ed. by D.G. Luttermoser, B.J. Smith, R.E. Stencel (Astronomical Society of the Pacific, San Francisco, 2009), p. 17Google Scholar
  91. 91.
    J.C.B. Papaloizou, Non-linear pulsations of upper main sequence stars-II.Direct numerical integrations. MNRAS. 162, 169 (1973)Google Scholar
  92. 92.
    A. Pasquali, N. Langer, W. Schmutz, O stars in transition. II. Fundamental properties and evolutionary status of Ofpe/WN9 stars from Hubble space telescope ultraviolet observations. ApJ. 478, 340–357 (1997)Google Scholar
  93. 93.
    A. Pasquali, A. Nota, L.J. Smith et al., Multiwavelength study of the nebula associated with the galactic LBV candidate HD 168625. AJ. 124, 1625–1635 (2002)ADSCrossRefGoogle Scholar
  94. 94.
    A. Pastorello, S.J. Smartt, S. Mattila et al., A giant outburst two years before the core-collapse of a massive star. Nature 447(7146), 829–832 (2007)ADSCrossRefGoogle Scholar
  95. 95.
    M. Patel, R.D. Oudmaijer, J.S. Vink et al., Spectropolarimetry of the massive post-red supergiants IRC + 10420 and HD 179821. MNRAS. 385, 967–978 (2008)ADSCrossRefGoogle Scholar
  96. 96.
    A.W.A. Pauldrach, J. Puls, Radiation-driven winds of hot stars. VIII – The bistable wind of the luminous blue variable P Cygni (B1 Ia/+/). A&A. 237, 409–424 (1990)Google Scholar
  97. 97.
    I. Pelupessy, H.J.G.L.M. Lamers, J.S. Vink, The radiation driven winds of rotating B[e] supergiants. A&A. 359, 695–706 (2000)Google Scholar
  98. 98.
    P. Podsiadlowski, P.C. Joss, S. Rappaport, A merger model for SN 1987 A. A&A. 227, L9–L12 (1990)ADSGoogle Scholar
  99. 99.
    J.L. Prieto, M.D. Kistler, T.A. Thompson, Discovery of the dust-enshrouded progenitor of SN 2008S with spitzer. ApJ. 681, 9 (2008)ADSCrossRefGoogle Scholar
  100. 100.
    J. Puls, U. Springmann, M. Lennon, Radiation driven winds of hot luminous stars. XIV. Line statistics and radiative driving. A&AS. 141, 23–64 (2000)Google Scholar
  101. 101.
    S.A. Pustilnik, A.L. Tepliakova, A.Y. Kniazev, A.N. Burenkov, Discovery of a massive variable star with Z = Zsolar/36 in the galaxy DDO 68. MNRAS. 388, L24–L28 (2008)ADSGoogle Scholar
  102. 102.
    S.D. Ryder, E.M. Sadler, R. Subrahmanyan et al., Modulations in the radio light curve of the Type IIb supernova 2001ig: evidence for a Wolf-Rayet binary progenitor? MNRAS. 349, 1093–1100 (2004)ADSCrossRefGoogle Scholar
  103. 103.
    G. Schaller, D. Schaerer, G. Meynet, A. Maeder, New grids of stellar models from 0.8 to 120 solar masses at Z = 0.020 and Z = 0.001. A&AS. 96, 269–331 (1992)Google Scholar
  104. 104.
    R.E. Schulte-Ladbeck, G.C. Clayton, D.J. Hillier, T.J. Harries, I.D. Howarth, The axisymmetric stellar wind of AG Carinae. ApJ. 429, 846–856 (1994)ADSCrossRefGoogle Scholar
  105. 105.
    N. Smith, Discovery of a nearby twin of SN 1987A’s nebula around the luminous blue variable HD 168625: was Sk -69 202 an LBV? AJ. 133, 1034–1040 (2007)ADSCrossRefGoogle Scholar
  106. 106.
    N. Smith, S.P. Owocki, On the role of continuum-driven eruptions in the evolution of very massive stars and population III stars. ApJ. 645, L45–L48 (2006)ADSCrossRefGoogle Scholar
  107. 107.
    L.J. Smith, A. Nota, A. Pasquali et al., Ejected nebulae as probes of the evolution of massive stars in the Large Magellanic Cloud. ApJ. 503, 278 (1998)ADSCrossRefGoogle Scholar
  108. 108.
    N. Smith, K. Davidson, Th.R. Gull, K. Ishibashi, D.J. Hillier, Latitude-dependent effects in the stellar wind of eta Carinae. ApJ. 586, 432–450 (2003)ADSCrossRefGoogle Scholar
  109. 109.
    N. Smith, J.S. Vink, A. de Koter, The missing Luminous Blue Variables and the bistability jump. ApJ. 615, 475–484 (2004)ADSCrossRefGoogle Scholar
  110. 110.
    N. Smith, W. Li, R.J. Foley et al., SN 2006gy: discovery of the most luminous supernova ever recorded, powered by the death of an extremely massive star like Eta Carinae. ApJ. 666, 1116 (2006)ADSCrossRefGoogle Scholar
  111. 111.
    N. Smith, M. Ganeshalingam, R. Chornock et al., ApJ. 697, 49 (2009)ADSCrossRefGoogle Scholar
  112. 112.
    A.M. Soderberg, R.A. Chevalier, S.R. Kulkarni, D.A. Frail, The radio and X-Ray luminous SN 2003bg and the circumstellar density variations around radio supernovae. ApJ. 651, 1005–1018 (2006)ADSCrossRefGoogle Scholar
  113. 113.
    O. Stahl, B. Wolf, Circumstellar shells around luminous emission-line stars in the Large Magellanic Cloud. A&A. 158, 371–381 (1986)ADSGoogle Scholar
  114. 114.
    O. Stahl, B. Wolf, G. Klare et al., R 127 – an S DOR type variable intermediate between Of and WN. A&A. 127, 49–62 (1983)ADSGoogle Scholar
  115. 115.
    O. Stahl, B. Wolf, G. Klare, A. Juettner, A. Cassatella, Observations of the new luminous blue variable R 110 of the Large Magellanic Cloud during an F star-phase. A&A. 228, 379–386 (1990)ADSGoogle Scholar
  116. 116.
    O. Stahl, I. Jankovics, J. Kovács et al., Long-term spectroscopic monitoring of the luminous blue variable AG Carinae. A&A. 375, 54–69 (2001)ADSCrossRefGoogle Scholar
  117. 117.
    C. Sterken, B. Wolf, Mass loss of B1 Ia-O supergiants. A&A. 70, 641–651 (1978)ADSGoogle Scholar
  118. 118.
    C. Sterken, E. Gosset, A. Juttner et al., HD160529 – a new galactic luminous blue variable. A&A. 247, 383–392 (1991)ADSGoogle Scholar
  119. 119.
    C. Sterken, A.M. van Genderen, A. Plummer, A.F. Jones, Wra 751, a luminous blue variable developing an S Doradus cycle. A&A. 484, 463–467 (2008)ADSCrossRefGoogle Scholar
  120. 120.
    R.B. Stothers, C.-W. Chin, Dynamical instability as the cause of the massive outbursts in Eta Carinae and other Luminous Blue Variables. ApJ. 408, L85–L88 (1993)ADSCrossRefGoogle Scholar
  121. 121.
    C. Trundle, D.J. Lennon, Understanding B-type supergiants in the low metallicity environment of the SMC II. A&A. 434, 677–689 (2005)ADSCrossRefGoogle Scholar
  122. 122.
    C. Trundle, R. Kotak, J.S. Vink, W.P.S. Meikle, SN 2005 gj: evidence for LBV supernovae progenitors? A&A. 483, L47–L50 (2008)ADSCrossRefGoogle Scholar
  123. 123.
    G. Umana, C.S. Buemi, C. Trigilio, J.L. Hora, G.G. Fazio, P. Leto, The dusty nebula surrounding HR car: a spitzer view. ApJ. 694, 697–703 (2009)ADSCrossRefGoogle Scholar
  124. 124.
    A.F. Valeev, O. Sholukhova, S. Fabrika, A new luminous variable in M33. MNRAS. 396, 21L–25L (2009)ADSGoogle Scholar
  125. 125.
    R. van Boekel, P. Kervella, M. Schöller, Direct measurement of the size and shape of the present-day stellar wind of eta Carinae. A&A. 410, L37–L40 (2003)ADSCrossRefGoogle Scholar
  126. 126.
    A.M. van Genderen, S Doradus variables in the galaxy and the Magellanic Clouds. A&A. 366, 508–531 (2001)ADSCrossRefGoogle Scholar
  127. 127.
    A.M. van Genderen, C. Sterken, Light variations of massive stars (alpha Cyg variables). XVIII. The B[e] supergiants S 18 in the SMC and R 66 = HDE 268835 and R 126 = HD 37974 in the LMC. A&A. 386, 926–935 (2002)Google Scholar
  128. 128.
    A. J. van Marle, N. Langer, G. Garcia-Segura, Constraints on gamma-ray burst and supernova progenitors through circumstellar absorption lines. II. Post-LBV Wolf-Rayet stars. A&A. 469, 948–948 (2007)Google Scholar
  129. 129.
    J.S. Vink, Constraining GRB progenitor models by probing Wolf-Rayet wind geometries in the Large Magellanic Cloud. A&A. 469, 707–711 (2007)ADSCrossRefGoogle Scholar
  130. 130.
    J.S. Vink, A. de Koter, Predictions of variable mass loss for Luminous Blue Variables. A&A. 393, 543–553 (2002)ADSCrossRefGoogle Scholar
  131. 131.
    J.S. Vink, A. de Koter, H.J.G.L.M. Lamers, On the nature of the bi-stability jump in the winds of early-type supergiants. A&A. 350, 181–196 (1999)Google Scholar
  132. 132.
    J.S. Vink, A. de Koter, H.J.G.L.M. Lamers, New theoretical mass-loss rates of O and B stars. A&A. 362, 295–309 (2000)Google Scholar
  133. 133.
    J.S. Vink, B. Davies, T.J. Harries, On the presence and absence of disks around O-type stars. A&A. 505, 743 (2009)ADSCrossRefGoogle Scholar
  134. 134.
    N.R. Walborn, Ofpe/WN9 circumstellar shells in the Large Magellanic Cloud. ApJ. 256, 452-459 (1982)ADSCrossRefGoogle Scholar
  135. 135.
    K. Weis, On the structure and kinematics of nebulae around LBVs and LBV candidates in the LMC. A&A. 408, 205–229 (2003)ADSCrossRefGoogle Scholar
  136. 136.
    S.M. White, R.A. Duncan, J. Lim et al., The radio source around Eta Carinae. ApJ. 429, 380–384 (1994)ADSCrossRefGoogle Scholar
  137. 137.
    P.A. Whitelock, M.W. Feast, C. Koen, G. Roberts, B.S. Carter, Variability of Eta-Carinae. MNRAS. 270, 364–372 (1994)Google Scholar
  138. 138.
    B. Wolf, Empirical amplitude-luminosity relation of S Doradus variables and extragalactic distances. A&A. 217, 87–91 (1989)ADSGoogle Scholar
  139. 139.
    S.E. Woosley, S. Blinnikov, A. Heger, Pulsational pair instability as an explanation for the most luminous supernovae. Nature 450, 390–392 (2007)ADSCrossRefGoogle Scholar
  140. 140.
    L.R. Yungelson, E.P.J. van den Heuvel, J.S. Vink, S.F. Portegies Zwart, A. de Koter, On the evolution and fate of super-massive stars. A&A. 477, 223–237 (2008)ADSCrossRefGoogle Scholar
  141. 141.
    T. Zethson, S. Johansson, K. Davidson, R.M. Humphreys, K. Ishibashi, D. Ebbets, Strange velocities in the equatorial ejecta of Eta Carinae. A&A. 344, 211–220 (1999)ADSGoogle Scholar
  142. 142.
    F.-J. Zickgraf, B. Wolf, C. Leitherer, I. Appenzeller, O. Stahl, B(e)-supergiants of the Magellanic Clouds. A&A. 163, 119–134 (1986)ADSGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  1. 1.Armagh ObservatoryArmaghNorthern Ireland

Personalised recommendations