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A blast wave from the 1843 eruption of η Carinae


Very massive stars shed much of their mass in violent precursor eruptions1 as luminous blue variables2 (LBVs) before reaching their most likely end as supernovae, but the cause of LBV eruptions is unknown. The nineteenth-century eruption of η Carinae, the prototype of these events3, ejected about 12 solar masses at speeds of 650 km s-1, with a kinetic energy of almost 1050 erg (ref. 4). Some faster material with speeds up to 1,000–2,000 km s-1 had previously been reported5,6,7,8 but its full distribution was unknown. Here I report observations of much faster material with speeds up to 3,500–6,000 km s-1, reaching farther from the star than the fastest material in previous reports5. This fast material roughly doubles the kinetic energy of the nineteenth-century event and suggests that it released a blast wave now propagating ahead of the massive ejecta. As a result, η Carinae’s outer shell now mimics a low-energy supernova remnant. The eruption has usually been discussed in terms of an extreme wind driven by the star’s luminosity2,3,9,10, but the fast material reported here indicates that it may have been powered by a deep-seated explosion rivalling a supernova, perhaps triggered by the pulsational pair instability11. This may alter interpretations of similar events seen in other galaxies.

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Figure 1: Example of the velocity structures seen in the He i λ10830 line.
Figure 2: Extremely fast nitrogen-rich material surrounding η Carinae.
Figure 3: Illustration of the possible geometry of η Carinae’s blast wave.


  1. Smith, N. & Owocki, S. P. On the role of continuum-driven eruptions in the evolution of very massive stars and Population III stars. Astrophys. J. 645, L45–L48 (2006)

    Article  ADS  CAS  Google Scholar 

  2. Humphreys, R. M. & Davidson, K. The luminous blue variables: Astrophysical geysers. Publ. Astron. Soc. Pacif. 106, 1025–1051 (1994)

    Article  ADS  Google Scholar 

  3. Davidson, K. & Humphreys, R. M. Eta Carinae and its environment. Annu. Rev. Astron. Astrophys. 35, 1–32 (1997)

    Article  ADS  Google Scholar 

  4. Smith, N. et al. Mass and kinetic energy of the Homunculus nebula around η Carinae. Astron. J. 125, 1458–1466 (2003)

    Article  ADS  Google Scholar 

  5. Smith, N. & Morse, J. A. Nitrogen and oxygen abundance variations in the outer ejecta of η Carinae: Evidence for recent chemical enrichment. Astrophys. J. 605, 854–863 (2004)

    Article  ADS  CAS  Google Scholar 

  6. Smith, N. Dissecting the Homunculus nebula around Eta Carinae with spatially resolved near-infrared spectroscopy. Mon. Not. R. Astron. Soc. 337, 1252–1268 (2002)

    Article  ADS  CAS  Google Scholar 

  7. Davidson, K., Smith, N., Gull, T. R., Ishibashi, K. & Hillier, D. J. The shape and orientation of the Homunculus nebula based on spectroscopic velocities. Astron. J. 121, 1569–1577 (2001)

    Article  ADS  Google Scholar 

  8. Currie, D. G., Dorland, B. N. & Kaufer, A. Discovery of a high velocity, spatially extended emission ‘shell’ in front of the southeast lobe of the η Carinae Homunculus. Astron. Astrophys. 389, L65–L68 (2002)

    Article  ADS  CAS  Google Scholar 

  9. Owocki, S. P., Gayley, K. G. & Shaviv, N. J. A porosity-length formalism for photon-tiring-limited mass loss from stars above the Eddington limit. Astrophys. J. 616, 525–541 (2004)

    Article  ADS  Google Scholar 

  10. Shaviv, N. J. The porous atmosphere of η Carinae. Astrophys. J. 532, L137–L140 (2000)

    Article  ADS  CAS  Google Scholar 

  11. Heger, A. & Woosley, S. F. The nucleosynthetic signature of Population III. Astrophys. J. 567, 532–543 (2002)

    Article  ADS  CAS  Google Scholar 

  12. Damineli, A., Conti, P. S. & Lopes, D. F. Eta Carinae: A long-period binary? N. Astron. 2, 107–117 (1997)

    Article  ADS  CAS  Google Scholar 

  13. Morse, J. A. et al. Hubble Space Telescope proper-motion measurements of the η Carinae nebula. Astrophys. J. 548, L207–L211 (2001)

    Article  ADS  Google Scholar 

  14. Smith, N. The structure of the Homunculus. I. Shape and latitude dependence from H2 and [Fe II] velocity maps of η Carinae. Astrophys. J. 644, 1151–1163 (2006)

    Article  ADS  CAS  Google Scholar 

  15. Smith, N., Davidson, K., Gull, T. R., Ishibashi, K. & Hillier, D. J. Latitude-dependent effects in the stellar wind of η Carinae. Astrophys. J. 586, 432–450 (2003)

    Article  ADS  CAS  Google Scholar 

  16. Walborn, N. R. The complex outer shell of Eta Carinae. Astrophys. J. 204, L17–L19 (1976)

    Article  ADS  CAS  Google Scholar 

  17. Walborn, N. R., Blanco, B. M. & Thackeray, A. D. Proper motions in the outer shell of Eta Carinae. Astrophys. J. 219, 498–503 (1978)

    Article  ADS  CAS  Google Scholar 

  18. Meaburn, J., Wolstencroft, R. D. & Walsh, J. R. Echelle and spectropolarimetric observations of the Eta Carinae nebulosity. Astron. Astrophys. 181, 333–342 (1987)

    ADS  CAS  Google Scholar 

  19. Weis, K., Duschl, W. J. & Bomans, D. J. High velocity structures in, and the X-ray emission from the LBV nebula around η Carinae. Astron. Astrophys. 367, 566–576 (2001)

    Article  ADS  CAS  Google Scholar 

  20. Davidson, K., Dufour, R. J., Walborn, N. R. & Gull, T. R. Ultraviolet and visual wavelength spectroscopy of gas around Eta Carinae. Astrophys. J. 305, 867–879 (1986)

    Article  ADS  CAS  Google Scholar 

  21. Smith, N., Brooks, K. J., Koribalski, B. & Bally, J. Cleaning up η Carinae: Detection of ammonia in the Homunculus nebula. Astrophys. J. 645, L41–L44 (2006)

    Article  ADS  CAS  Google Scholar 

  22. Pittard, J. M. & Corcoran, M. F. In hot pursuit of the hidden companion of η Carinae: An X-ray determination of the wind parameters. Astron. Astrophys. 383, 636–647 (2002)

    Article  ADS  Google Scholar 

  23. Seward, F. D. et al. Early Chandra X-ray observations of η Carinae. Astrophys. J. 553, 832–836 (2001)

    Article  ADS  Google Scholar 

  24. Woosley, S. F., Blinnikov, S. & Heger, A. Pulsational pair instability as an explanation for the most luminous supernovae. Nature 450, 390–392 (2007)

    Article  ADS  CAS  Google Scholar 

  25. Smith, N. et al. SN 2006gy: Discovery of the most luminous supernova ever recorded, powered by the death of an extremely massive star like η Carinae. Astrophys. J. 666, 1116–1128 (2007)

    Article  ADS  CAS  Google Scholar 

  26. Foley, R. J. et al. 2006jc: A Wolf–Rayet star exploding in a dense He-rich circumstellar medium. Astrophys. J. 657, L105–L108 (2007)

    Article  ADS  CAS  Google Scholar 

  27. Pastorello, A. et al. A giant outburst two years before the core-collapse of a massive star. Nature 447, 829–832 (2007)

    Article  ADS  CAS  Google Scholar 

  28. Van Dyk, S. D. et al. SN 1997bs in M66: Another extragalactic η Carinae analog? Publ. Astron. Soc. Pacif. 112, 1532–1541 (2000)

    Article  ADS  Google Scholar 

  29. Goodrich, R. W., Stringfellow, G. S., Penrod, G. D. & Filippenko, A. V. S. N. 1961V: An extragalactic Eta Carinae analog? Astrophys. J. 342, 908–916 (1989)

    Article  ADS  CAS  Google Scholar 

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I acknowledge continuing collaboration and relevant discussions with the supernova group at the University of California at Berkeley.

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Correspondence to Nathan Smith.

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Smith, N. A blast wave from the 1843 eruption of η Carinae. Nature 455, 201–203 (2008).

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