An expanding radio nebula produced by a giant flare from the magnetar SGR 1806-20

B. M. Gaensler, C. Kouveliotou, J. D. Gelfand, G. B. Taylor, D. Eichler, R. A.M.J. Wijers, J. Granot, E. Ramirez-Ruiz, Y. E. Lyubarsky, R. W. Hunstead, D. Campbell-Wilson, A. J. Van Der Horst, M. A. McLaughlin, R. P. Fender, M. A. Garrett, K. J. Newton-McGee, D. M. Palmer, N. Gehrels, P. M. Woods

Research output: Contribution to journalArticle


Soft γ-ray repeaters (SGRs) are 'magnetars', a small class of slowly spinning neutron stars with extreme surface magnetic fields, B ≈ 10 15 gauss (refs 1-3). On 27 December 2004, a giant flare was detected from the magnetar SGR 1806-20 (ref. 2), only the third such event recorded. This burst of energy was detected by a variety of instruments and even caused an ionospheric disturbance in the Earth's upper atmosphere that was recorded around the globe. Here we report the detection of a fading radio afterglow produced by this outburst, with a luminosity 500 times larger than the only other detection of a similar source. From day 6 to day 19 after the flare from SGR 1806-20, a resolved, linearly polarized, radio nebula was seen, expanding at approximately a quarter of the speed of light. To create this nebula, at least 4 × 10 43 ergs of energy must have been emitted by the giant flare in the form of magnetic fields and relativistic particles.

Original languageEnglish (US)
Pages (from-to)1104-1106
Number of pages3
Issue number7037
StatePublished - Apr 28 2005


ASJC Scopus subject areas

  • General

Cite this

Gaensler, B. M., Kouveliotou, C., Gelfand, J. D., Taylor, G. B., Eichler, D., Wijers, R. A. M. J., Granot, J., Ramirez-Ruiz, E., Lyubarsky, Y. E., Hunstead, R. W., Campbell-Wilson, D., Van Der Horst, A. J., McLaughlin, M. A., Fender, R. P., Garrett, M. A., Newton-McGee, K. J., Palmer, D. M., Gehrels, N., & Woods, P. M. (2005). An expanding radio nebula produced by a giant flare from the magnetar SGR 1806-20. Nature, 434(7037), 1104-1106.