Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

A novel explosive process is required for the γ-ray burst GRB 060614


Over the past decade, our physical understanding of γ-ray bursts (GRBs) has progressed rapidly, thanks to the discovery and observation of their long-lived afterglow emission. Long-duration (2 s) GRBs are associated with the explosive deaths of massive stars (‘collapsars’, ref. 1), which produce accompanying supernovae2,3,4,5; the short-duration (2 s) GRBs have a different origin, which has been argued to be the merger of two compact objects6,7,8,9. Here we report optical observations of GRB 060614 (duration 100 s, ref. 10) that rule out the presence of an associated supernova. This would seem to require a new explosive process: either a massive collapsar that powers a GRB without any associated supernova, or a new type of ‘engine’, as long-lived as the collapsar but without a massive star. We also show that the properties of the host galaxy (redshift z = 0.125) distinguish it from other long-duration GRB hosts and suggest that an entirely new type of GRB progenitor may be required.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Temporal evolution of the optical transient associated with GRB 060614.
Figure 2: HST observations of the location of GRB 060614.

Similar content being viewed by others


  1. MacFadyen, A. I., Woosley, S. E. & Heger, A. Supernovae, jets, and collapsars. Astrophys. J. 550, 410–425 (2001)

    Article  ADS  Google Scholar 

  2. Galama, T. J. et al. An unusual supernova in the error box of the γ-ray burst of 25 April 1998. Nature 395, 670–672 (1998)

    Article  ADS  CAS  Google Scholar 

  3. Stanek, K. Z. et al. Spectroscopic discovery of the supernova 2003dh associated with GRB 030329. Astrophys. J. 591, L17–L20 (2003)

    Article  ADS  CAS  Google Scholar 

  4. Hjorth, J. et al. A very energetic supernova associated with the γ-ray burst of 29 March 2003. Nature 423, 847–850 (2003)

    Article  ADS  CAS  Google Scholar 

  5. Malesani, D. et al. SN 2003lw and GRB 031203: A bright supernova for a faint gamma-ray burst. Astrophys. J. 609, L5–L8 (2004)

    Article  ADS  CAS  Google Scholar 

  6. Gehrels, N. et al. A short γ-ray burst apparently associated with an elliptical galaxy at redshift z = 0.225. Nature 437, 851–854 (2005)

    Article  ADS  CAS  Google Scholar 

  7. Bloom, J. S. et al. Closing in on a short-hard burst progenitor: Constraints from early-time optical imaging and spectroscopy of a possible host galaxy of GRB 050509b. Astrophys. J. 638, 354–368 (2006)

    Article  ADS  CAS  Google Scholar 

  8. Berger, E. et al. The afterglow and elliptical host galaxy of the short γ-ray burst GRB 050724. Nature 438, 988–990 (2005)

    Article  ADS  CAS  Google Scholar 

  9. Hjorth, J. et al. The optical afterglow of the short γ-ray burst GRB 050709. Nature 437, 859–861 (2005)

    Article  ADS  CAS  Google Scholar 

  10. Parsons, A. M. et al. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart. GCN Circ. 5252, (2006)

  11. Gehrels, N. et al. A new γ-ray burst classification scheme from GRB 060614. Nature doi:10.1038/nature05376 (this issue).

  12. Golenetskii, S. et al. Konus-wind observation of GRB 060614. GCN Circ. 5264, (2006)

  13. Pian, E. et al. An optical supernova associated with the X-ray flash XRF 060218. Nature 442, 1011–1013 (2006)

    Article  ADS  CAS  Google Scholar 

  14. Fynbo, J. P. U. et al. No supernovae associated with two long-duration γ-ray bursts. Nature doi:10.1038/nature05375 (this issue).

  15. Modjaz, M. et al. Early-time photometry and spectroscopy of the fast evolving SN 2006aj associated with GRB 060218. Astrophys. J. 645, L21–L24 (2006)

    Article  ADS  CAS  Google Scholar 

  16. Della Valle, M. et al. An enigmatic long-lasting γ-ray burst not accompanied by a bright supernova. Nature doi:10.1038/nature05374 (this issue).

  17. Pastorello, A. et al. Low-luminosity type II supernovae: spectroscopic and photometric evolution. Mon. Not. R. Astron. Soc. 347, 74–94 (2004)

    Article  ADS  CAS  Google Scholar 

  18. Soderberg, A. M. et al. An HST study of the supernovae accompanying GRB 040924 and GRB 041006. Astrophys. J. 636, 391–399 (2006)

    Article  ADS  CAS  Google Scholar 

  19. Christensen, L., Hjorth, J. & Gorosabel, J. UV star-formation rates of GRB host galaxies. Astron. Astrophys. 425, 913–926 (2004)

    Article  ADS  CAS  Google Scholar 

  20. Fruchter, A. S. et al. Long γ-ray bursts and core-collapse supernovae have different environments. Nature 441, 463–468 (2006)

    Article  ADS  CAS  Google Scholar 

  21. Zeh, A., Klose, S. & Hartmann, D. H. A systematic analysis of supernova light in gamma-ray burst afterglows. Astrophys. J. 609, 952–961 (2004)

    Article  ADS  CAS  Google Scholar 

  22. Fox, D. B. et al. The afterglow of GRB 050709 and the nature of the short-hard γ-ray bursts. Nature 437, 845–850 (2005)

    Article  ADS  CAS  Google Scholar 

  23. Narayan, R., Piran, T. & Kumar, P. Accretion models of gamma-ray bursts. Astrophys. J. 557, 949–957 (2001)

    Article  ADS  Google Scholar 

  24. French, J., Melady, G., Hanlon, L., Jelinek, M. & Kubanek, P. GRB060614: Watcher observation. GCN Circ. 5257, (2006)

  25. Gal-Yam, A., Ofek, E. O. & Shemmer, O. Supernova 2002ap: the first month. Mon. Not. R. Astron. Soc. 332, L73–L77 (2002)

    Article  ADS  Google Scholar 

  26. Foley, R. J. et al. Optical photometry and spectroscopy of the SN 1998bw-like type Ic supernova 2002ap. Publ. Astron. Soc. Pacif. 115, 1220–1235 (2003)

    Article  ADS  Google Scholar 

  27. Gal-Yam, A. et al. On the progenitor of SN 2005gl and the nature of type IIn supernovae. Astrophys. J. (in the press); preprint at 〈〉 (2006)

  28. Gal-Yam, A., Maoz, D. & Sharon, K. Supernovae in deep Hubble Space Telescope galaxy cluster fields: cluster rates and field counts. Mon. Not. R. Astron. Soc. 332, 37–48 (2002)

    Article  ADS  Google Scholar 

  29. Ofek, E. O. et al. GRB 060505: A possible short-duration gamma-ray burst in a star-forming region at a redshift of z=0.09. Astrophys. J. (submitted).

Download references


A.G. and E.B. acknowledge support by NASA through Hubble Fellowships. S.R.K. is supported by NSF and NASA. The HST campaign combined resources from our approved programmes (principal investigators S.R.K. and D.B.F.).

Author information

Authors and Affiliations


Corresponding author

Correspondence to A. Gal-Yam.

Ethics declarations

Competing interests

Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Notes

This file contains Supplementary Notes describing the association of GRB 060614 with the proposed z=0.125 host galaxy and host properties and GRB environment; Supplementary Figures 1-3 with legends and Supplementary Data.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gal-Yam, A., Fox, D., Price, P. et al. A novel explosive process is required for the γ-ray burst GRB 060614. Nature 444, 1053–1055 (2006).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing