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.

A fast radio burst associated with a Galactic magnetar


Since their discovery in 20071, much effort has been devoted to uncovering the sources of the extragalactic, millisecond-duration fast radio bursts (FRBs)2. A class of neutron stars known as magnetars is a leading candidate source of FRBs3,4. Magnetars have surface magnetic fields in excess of 1014 gauss, the decay of which powers a range of high-energy phenomena5. Here we report observations of a millisecond-duration radio burst from the Galactic magnetar SGR 1935+2154, with a fluence of 1.5 ± 0.3 megajansky milliseconds. This event, FRB 200428 (ST 200428A), was detected on 28 April 2020 by the STARE2 radio array6 in the 1,281–1,468 megahertz band. The isotropic-equivalent energy released in FRB 200428 is 4 × 103 times greater than that of any radio pulse from the Crab pulsar—previously the source of the brightest Galactic radio bursts observed on similar timescales7. FRB 200428 is just 30 times less energetic than the weakest extragalactic FRB observed so far8, and is drawn from the same population as the observed FRB sample. The coincidence of FRB 200428 with an X-ray burst9,10,11 favours emission models that describe synchrotron masers or electromagnetic pulses powered by magnetar bursts and giant flares3,4,12,13. The discovery of FRB 200428 implies that active magnetars such as SGR 1935+2154 can produce FRBs at extragalactic distances.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Time series and dynamic spectrum of FRB 200428.
Fig. 2: STARE2 localization of FRB 200428.
Fig. 3: Phase space of centimetre-wavelength radio transient events.

Data availability

Data are available upon request. These data are in a public archive by the Caltech Library at .

Code availability

Custom code is available at The code used to fit the burst profiles is available on request.


  1. 1.

    Lorimer, D. R. et al. A bright millisecond radio burst of extragalactic origin. Science 318, 777 (2007).

    ADS  CAS  Article  Google Scholar 

  2. 2.

    Petroff, E., Hessels, J. W. T. & Lorimer, D. R. Fast radio bursts. Astron. Astrophys. Rev. 27, 4 (2019).

    ADS  Article  Google Scholar 

  3. 3.

    Lyubarsky, Y. A model for fast extragalactic radio bursts. Mon. Not. R. Astron. Soc. 442, L9 (2014).

    ADS  Article  Google Scholar 

  4. 4.

    Beloborodov, A. M. A flaring magnetar in FRB 121102? Astrophys. J. Lett. 843, 26 (2017).

    ADS  Article  Google Scholar 

  5. 5.

    Kaspi, V. M. & Beloborodov, A. M. Magnetars. Annu. Rev. Astron. Astrophys. 55, 261 (2017).

    ADS  CAS  Article  Google Scholar 

  6. 6.

    Bochenek, C. D. et al. STARE2: detecting fast radio bursts in the Milky Way. Publ. Astron. Soc. Pacif. 132, 034202 (2020).

    ADS  Article  Google Scholar 

  7. 7.

    Cordes, J. M., Bhat, N. D. R., Hankins, T. H., McLaughlin, M. A. & Kern, J. The brightest pulses in the Universe: multifrequency observations of the Crab pulsar’s giant pulses. Astrophys. J. 612, 375 (2004).

    ADS  Article  Google Scholar 

  8. 8.

    Marcote, B. et al. A repeating fast radio burst source localized to a nearby spiral galaxy. Nature 577, 190–194 (2020).

    ADS  CAS  Article  Google Scholar 

  9. 9.

    Mereghetti, S. et al. INTEGRAL discovery of a burst with associated radio emission from the magnetar SGR 1935+2154. Astrophys. J. Lett. 898, 29 (2020).

    ADS  Article  Google Scholar 

  10. 10.

    Ridnaia, A. et al. A peculiar hard X-ray counterpart of a Galactic fast radio burst. Preprint at (2020).

  11. 11.

    Li, C. K. et al. Identification of a non-thermal X-ray burst with the Galactic magnetar SGR J1935+2154 and a fast radio burst with Insight-HXMT. Preprint at (2020).

  12. 12.

    Metzger, B. D., Margalit, B. & Sironi, L. Fast radio bursts as synchrotron maser emission from decelerating relativistic blast waves. Mon. Not. R. Astron. Soc. 485, 4091–4106 (2019).

    ADS  CAS  Article  Google Scholar 

  13. 13.

    Lyubarsky, Y. Fast radio bursts from reconnection in magnetar magnetosphere. Astrophys. J. 897, 1 (2020).

    ADS  Article  Google Scholar 

  14. 14.

    Barthelmy, S. D. et al. Swift detection of multiple bursts from SGR J1935+2154. GRB Circ. Netw. 27657, (2020).

  15. 15.

    Scholz, P. et al. A bright millisecond-timescale radio burst from the direction of the Galactic magnetar SGR J1935+2154. Astron. Telegr. 13681, (2020).

  16. 16.

    Zhang, C. F. et al. A highly polarised radio burst detected from SGR J1935+2154 by FAST. Astron. Telegr. 13699, (2020).

  17. 17.

    Kothes, R., Sun, X., Gaensler, B. & Reich, W. A radio continuum and polarization study of SNR G57.2+0.8 associated with magnetar SGR J1935+2154. Astrophys. J. 852, 54 (2018).

    ADS  Article  Google Scholar 

  18. 18.

    Zhou, P. et al. Revisiting the distance, environment and supernova properties of SNR G57.2+0.8 that hosts SGR J1935+2154. Preprint at (2020).

  19. 19.

    Kozlova, A. V. et al. The first observation of an intermediate flare from SGR J1935+2154. Mon. Not. R. Astron. Soc. 460, 2008–2014 (2016).

    ADS  CAS  Article  Google Scholar 

  20. 20.

    Kuzmin, A. D. Giant pulses of pulsar radio emission. Astrophys. Space Sci. 308, 563–567 (2007).

    ADS  Article  Google Scholar 

  21. 21.

    CHIME/FRB. A bright millisecond-duration radio burst from a Galactic magnetar. Nature (2020).

  22. 22.

    Sokolowski, M. et al. No low-frequency emission from extremely bright fast radio bursts. Astrophys. J. Lett. 867, 12 (2018).

    ADS  Article  Google Scholar 

  23. 23.

    Bannister, K. et al. A single fast radio burst localized to a massive galaxy at cosmological distance. Science 365, 565 (2019).

    ADS  CAS  Article  Google Scholar 

  24. 24.

    Ravi, V. et al. A fast radio burst localized to a massive galaxy. Nature 572, 352–354 (2019).

    ADS  CAS  Article  Google Scholar 

  25. 25.

    Prochaska, J. X. et al. The low density and magnetization of a massive galaxy halo exposed by a fast radio burst. Science 366, 231 (2019).

    ADS  CAS  Article  Google Scholar 

  26. 26.

    Macquart, J. P. et al. A census of baryons in the Universe from localized fast radio bursts. Nature 581, 391–395 (2020).

    ADS  CAS  Article  Google Scholar 

  27. 27.

    Lu, W. & Kumar, P. On the radiation mechanism of repeating fast radio bursts. Mon. Not. R. Astron. Soc. 477, 2470-2493 (2018).

    ADS  CAS  Article  Google Scholar 

  28. 28.

    Archibald, R. F., Kaspi, V. M., Tendulkar, S. P. & Scholz, P. The 2016 outburst of PSR J1119–6127: cooling and a spin-down-dominated glitch. Astrophys. J. 869, 180 (2018).

    ADS  CAS  Article  Google Scholar 

  29. 29.

    Lu, W. & Piro, A. L. Implications from ASKAP fast radio burst statistics. Astrophys. J. 883, 40 (2019).

    ADS  CAS  Article  Google Scholar 

  30. 30.

    Jarrett, T. H. et al. The WISE extended source catalog (WXSC). I. The 100 largest galaxies. Astrophys. J. Suppl. Ser. 245, 25 (2019).

    ADS  CAS  Article  Google Scholar 

  31. 31.

    Manchester, R. N. & Taylor, J. H. Pulsars (W. H. Freeman, 1977).

  32. 32.

    Keane, E. F. The future of fast radio burst science. Nat. Astron. 2, 865–872 (2018).

    ADS  Article  Google Scholar 

  33. 33.

    Villadsen, J. & Hallinan, G. Ultra-wideband detection of 22 coherent radio bursts on M dwarfs. Astrophys. J. 871, 214 (2019).

    ADS  CAS  Article  Google Scholar 

  34. 34.

    Kawai, H. et al. Telescope array experiment. Nucl. Phys. B 175/176, 221–226 (2008).

    Article  Google Scholar 

  35. 35.

    Ravi, V. The observed properties of fast radio bursts. Mon. Not. R. Astron. Soc. 482, 1966–1978 (2019).

    ADS  CAS  Article  Google Scholar 

  36. 36.

    Cordes, J. M. & Chatterjee, S. Fast radio bursts: an extragalactic enigma. Annu. Rev. Astron. Astrophys. 57, 417 (2019).

    ADS  Article  Google Scholar 

  37. 37.

    Kirsten, R. Detection of two bright FRB-like radio bursts from magnetar SGR J1935+2154 during a multi-frequency monitoring campaign. Preprint at (2020).

  38. 38.

    Yao, J. M., Manchester, R. N. & Wang, N. A new electron-density model for estimation of pulsar and FRB distances. Astrophys. J. 835, 29 (2017).

    ADS  Article  Google Scholar 

  39. 39.

    Cordes, J. M. & Lazio, T. J. W. NE2001. I. A new model for the Galactic distribution of free electrons and its fluctuations. Preprint at (2002).

  40. 40.

    Hessels, J. W. T. et al. FRB 121102 bursts show complex time-frequency structure. Astrophys. J. 876, L23 (2019).

    ADS  CAS  Article  Google Scholar 

  41. 41.

    Astropy Collaboration et al. The Astropy project: building an open-science project and status of the v2.0 core package. Astron. J. 156, 123 (2018).

    ADS  Article  Google Scholar 

  42. 42.

    Licquia, T. C. & Newman, J. A. Improved estimates of the Milky Way’s stellar mass and star formation rate from hierarchical Bayesian meta-analysis. Astrophys. J. 806, 96 (2015).

    ADS  Article  Google Scholar 

  43. 43.

    Salim, S. et al. UV star formation rates in the local Universe. Astrophys. J. Suppl. Ser. 173, 267 (2007).

    ADS  CAS  Article  Google Scholar 

  44. 44.

    Lu, W. et al. A unified picture of Galactic and cosmological fast radio bursts. Mon. Not. R. Astron. Soc. 498, 1397–1405 (2020).

    ADS  Article  Google Scholar 

Download references


We thank the then director of OVRO, A. Readhead, for funds (derived from the Alan Moffet Funds) that allowed us to start this project. The Caltech and Jet Propulsion Laboratory President’s and Director’s Fund enabled us to build the second system at Goldstone and the third system near Delta, Utah. We are thankful to Caltech and the Jet Propulsion Laboratories for the second round of funding. C.D.B., a PhD student, was partially supported by the Heising-Simons foundation. We also thank S. Weinreb and D. Hodge for building the front-end and back-end boxes, J. Lagrange for support at GDSCC, J. Matthews and the Telescope Array Collaboration for assistance at Delta, and the entire OVRO staff, in particular J. Lamb, D. Woody and M. Catha, for support. We thank S. Phinney and W. Lu for comments on the manuscript. A portion of this research was performed at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. This research was additionally supported by the National Science Foundation under grant AST-1836018. This research made use of Astropy, a community-developed core Python package for Astronomy. This research also used the SIMBAD database, operated at CDS, Strasbourg, France.

Author information




S.R.K., C.D.B., D.L.M., V.R., K.V.B. and G.H. conceived and developed the STARE2 concept and observing strategy. C.D.B., D.L.M., K.V.B., J.K. and S.R.K. led the construction and initial deployment of STARE2. C.D.B., D.L.M., K.V.B., V.R., J.K. and G.H. designed and built the STARE2 subsystems. C.D.B., D.L.M. and K.V.B. commissioned STARE2. C.D.B. operated STARE2, performed the localization and transient rate analyses, as well as the searches for sub-threshold events and events associated with other SGR flares. V.R. extracted the properties of the burst. C.D.B. and V.R. led the writing of the manuscript with the assistance of all co-authors.

Corresponding author

Correspondence to C. D. Bochenek.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature thanks Evan Keane and Amanda Weltman for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended Data Fig. 1 Time series and dynamic spectrum of FRB 200428 at each station.

Top, time series at each station referenced to the arrival time at OVRO at ν = 1,529.267578 MHz. Bottom, dynamic spectra at each station. The data shown in all panels were processed in the same way as those in Fig. 1. We have not corrected for the spectral response at each station. The blue bars in the Delta dynamic spectrum indicate frequencies affected by radio frequency interference that were excised from the data.

Extended Data Fig. 2 Fits to data on FRB 200428 in four sub-bands.

Black lines indicate the raw data and blue lines show the best-fit model. The sub-band centre frequencies are indicated beside each plot.

Extended Data Fig. 3 Volumetric rates of FRBs.

Volumetric rate, Φ(>E), calculated from the radio burst from SGR 1935+2154 (red cross) compared with the extrapolated luminosity function of bright FRBs29 (blue-shaded region). The black crosses represent the volumetric rate of FRBs determined from the ASKAP Fly’s Eye sample29. We note that correlated probabilities between the parameters of the luminosity function are not taken into account, leading to an overestimate of the uncertainty in the blue-shaded region; see ref. 43 for a similar plot in which they are taken into account. The volumetric rate was calculated by modelling the population of Galactic fast radio transients as a Poisson process and assuming that these fast radio transients track star formation. The uncertainties on this measurement are 1σ statistical uncertainties, in addition to the maximum range of possible distances to SGR 1935+2154 (4–16 kpc)39. We also show the energy of the weakest burst detected from FRB 180916.J0158+65—a repeating FRB—for comparison8. The volumetric rate of Galactic fast radio transients is consistent with extrapolating the luminosity function of bright FRBs to the energy of FRB 200428.

Extended Data Fig. 4 Upper limits on fast radio transients from other flares of SGR 1935+2154 observable by STARE2.

The ordinate shows the 7.3σ upper limit on the fluence of a potential burst in Jy ms1/2, and the abscissa shows the times (in MJD) of reported flares from SGR 1935+2154. The derivation of the upper limits is described in Methods. We note that our three-station system was observing only during the flares between MJD 58966 and MJD 58987, shown in black. For the other flares, only our stations at OVRO and GDSCC were observing, shown in red. We show FRB 200428 in blue; the error bar represents the standard error in the measured fluence.

Extended Data Table 1 STARE2 7.3σ upper limits on reported X-ray bursts from SGR 1935+2154 that occurred in the STARE2 field of view
Extended Data Table 2 STARE2 7.3σ upper limits on reported X-ray bursts from SGR 1935+2154 that occurred in the STARE2 field of view

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Bochenek, C.D., Ravi, V., Belov, K.V. et al. A fast radio burst associated with a Galactic magnetar. Nature 587, 59–62 (2020).

Download citation

Further reading


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