Letter | Published:

Imaging coronal magnetic-field reconnection in a solar flare

Nature Physics volume 9, pages 489493 (2013) | Download Citation

Abstract

Magnetic-field reconnection is believed to play a fundamental role in magnetized plasma systems throughout the Universe1, including planetary magnetospheres, magnetars and accretion disks around black holes. This letter presents extreme ultraviolet and X-ray observations of a solar flare showing magnetic reconnection with a level of clarity not previously achieved. The multi-wavelength extreme ultraviolet observations from SDO/AIA show inflowing cool loops and newly formed, outflowing hot loops, as predicted. RHESSI X-ray spectra and images simultaneously show the appearance of plasma heated to >10 MK at the expected locations. These two data sets provide solid visual evidence of magnetic reconnection producing a solar flare, validating the basic physical mechanism of popular flare models. However, new features are also observed that need to be included in reconnection and flare studies, such as three-dimensional non-uniform, non-steady and asymmetric evolution.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    & Magnetic Reconnection (Cambridge Univ. Press, 2000).

  2. 2.

    , & Magnetic reconnection. Rev. Mod. Phys. 82, 603–664 (2010).

  3. 3.

    et al. Modelling loop-top X-ray source and reconnection outflows in solar flares with intense lasers. Nature Phys. 6, 984–987 (2010).

  4. 4.

    & Rapid magnetic reconnection in the Earth’s magnetosphere mediated by whistler waves. Nature 410, 557–560 (2001).

  5. 5.

    , , , & In situ detection of collisionless reconnection in the Earth’s magnetotail. Nature 412, 414–417 (2001).

  6. 6.

    Physics of the Solar Corona. An Introduction (Praxis, 2004).

  7. 7.

    et al. An observational overview of solar flares. Space Sci. Rev. 159, 19–106 (2011).

  8. 8.

    & Solar flares: Magnetohydrodynamic processes. Living Rev. Solar Phys. 8, 6 (2011).

  9. 9.

    Coronal mass ejections: Models and their observational basis. Living Rev. Solar Phys. 8, 1 (2011).

  10. 10.

    , , , & Clear evidence of reconnection inflow of a solar flare. Astrophys. J. 546, L69–L72 (2001).

  11. 11.

    & Observations of the magnetic reconnection signature of an M2 Flare on 2000 March 23. Astrophys. J. 703, 877–882 (2009).

  12. 12.

    , & Direct observation of high-speed plasma outflows produced by magnetic reconnection in solar impulsive events. Astrophys. J. 661, L207–L210 (2007).

  13. 13.

    et al. Low-altitude reconnection inflow–outflow observations during a 2010 November 3 solar eruption. Astrophys. J. 754, 13–26 (2012).

  14. 14.

    , , & Simultaneous observation of reconnection inflow and outflow associated with the 2010 August 18 solar flare. Astrophys. J. 745, L6 (2012).

  15. 15.

    et al. Observation of a solar flare at the limb with the YOHKOH Soft X-ray Telescope. Publ. Astron. Soc. Jpn 44, L63–L69 (1992).

  16. 16.

    & Evidence for the formation of a large-scale current sheet in a solar flare. Astrophys. J. 596, L251–L254 (2003).

  17. 17.

    et al. Direct observations of the magnetic reconnection site of an eruption on 2003 November 18. Astrophys. J. 622, 1251–1264 (2005).

  18. 18.

    et al. A Reconnecting current sheet imaged in a solar flare. Astrophys. J. 723, L28–L33 (2010).

  19. 19.

    , , , & loop-top hard X-ray source in a compact solar flare as evidence for magnetic reconnection. Nature 371, 495–497 (1994).

  20. 20.

    et al. Observations of X-ray jets with the YOHKOH soft X-ray telescope. Publ. Astron. Soc. Jpn. 44, 173–179 (1992).

  21. 21.

    , & The solar dynamics observatory (SDO). Sol. Phys. 275, 3–15 (2012).

  22. 22.

    et al. The atmospheric imaging assembly (AIA) on the solar dynamics observatory (SDO). Sol. Phys. 275, 17–40 (2012).

  23. 23.

    et al. The Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). Sol. Phys. 210, 3–32 (2002).

  24. 24.

    , , & Episodic X-Ray emission accompanying the activation of an eruptive prominence: Evidence of episodic magnetic reconnection. Astrophys. J. 698, 632–640 (2009).

  25. 25.

    & A model for the origin of high density in looptop X-ray sources. Astrophys. J. 740, 73–90 (2011).

  26. 26.

    & in Subsurface and Atmospheric Influences on Solar Activity, ASP Conference Series Vol. 383 (eds Howe, R., Komm, R. W., Balasubramaniam, K. S. & Petrie, G. J. D.) 373 (Astronomical Society of the Pacific, 2008).

  27. 27.

    in The Physics of Solar Flares, NASA SP-50 (ed. Hess, W. N.) 425 (NASA, 1964).

  28. 28.

    & The magnetic nature of solar flares. Astron. Astrophys. Rev. 10, 313–377 (2002).

  29. 29.

    , , , & Analysis of RHESSI flares using a radio astronomical technique. Sol. Phys. 240, 241–252 (2007).

  30. 30.

    comparison of solar x-ray line emission with microwave emission during flares. Astrophys. J. 153, L59 (1968).

Download references

Acknowledgements

The authors dedicate this paper to the late RHESSI PI, R. P. Lin, in acknowledgement of his inspirational efforts that made possible the high-quality solar X-ray data used in this paper. RHESSI is a NASA Small Explorer Mission. The GOES is a joint effort of NASA and the National Oceanic and Atmospheric Administration (NOAA). The SDO is a mission for NASA’s Living With a Star (LWS) Program. The work of Y.S. and A.M.V. was supported by the European Community Framework Programme 7, High Energy Solar Physics data in Europe (HESPE), grant agreement No. 263086. Y.S. also acknowledges NSFC 11233008. The work of G.H. was supported by a NASA Guest Investigator Grant and the RHESSI programme. The work of T.W. was supported by NASA grant NNX12AB34G and NASA Cooperative Agreement NNG11PL10A to C.U.A. M.T. acknowledges the Austrian Science Fund (FWF): V195-N16. W.G. acknowledges 2011CB811402 and NSFC 11233008.

Author information

Affiliations

  1. Kanzelhöhe Observatory-IGAM, Institute of Physics, University of Graz, Universitaetsplatz 5/II, 8010 Graz, Austria

    • Yang Su
    • , Astrid M. Veronig
    •  & Manuela Temmer
  2. Solar Physics Laboratory (Code 671), Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA

    • Gordon D. Holman
    • , Brian R. Dennis
    •  & Tongjiang Wang
  3. Department of Physics, the Catholic University of America, Washington DC 20064, USA

    • Tongjiang Wang
  4. Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China

    • Weiqun Gan

Authors

  1. Search for Yang Su in:

  2. Search for Astrid M. Veronig in:

  3. Search for Gordon D. Holman in:

  4. Search for Brian R. Dennis in:

  5. Search for Tongjiang Wang in:

  6. Search for Manuela Temmer in:

  7. Search for Weiqun Gan in:

Contributions

Y.S. analysed the data, wrote the text and led the discussion. A.M.V., G.D.H., B.R.D., T.W., M.T. and W.G. contributed to the interpretation of the data and helped to improve the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Yang Su.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    Supplementary Information

Videos

  1. 1.

    Supplementary Movie

    Supplementary movie 1

  2. 2.

    Supplementary Movie

    Supplementary movie 2

  3. 3.

    Supplementary Movie

    Supplementary movie 3

  4. 4.

    Supplementary Movie

    Supplementary movie 4

  5. 5.

    Supplementary Movie

    Supplementary movie 5

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nphys2675

Further reading