Space Science Reviews

, 159:263

Microflares and the Statistics of X-ray Flares


    • School of Physics & AstronomyUniversity of Glasgow
  • H. S. Hudson
    • Space Sciences LaboratoryUniversity of California at Berkeley
  • M. Battaglia
    • School of Physics & AstronomyUniversity of Glasgow
  • S. Christe
    • NASA Goddard Space Flight Center
  • J. Kašparová
    • Astronomický ústav AV ČR
  • S. Krucker
    • Space Sciences LaboratoryUniversity of California at Berkeley
  • M. R. Kundu
    • Dept. of AstronomyUniv. of Maryland
  • A. Veronig
    • Institute of Physics/IGAMUniversity of Graz

DOI: 10.1007/s11214-010-9705-4

Cite this article as:
Hannah, I.G., Hudson, H.S., Battaglia, M. et al. Space Sci Rev (2011) 159: 263. doi:10.1007/s11214-010-9705-4


This review surveys the statistics of solar X-ray flares, emphasising the new views that RHESSI has given us of the weaker events (the microflares). The new data reveal that these microflares strongly resemble more energetic events in most respects; they occur solely within active regions and exhibit high-temperature/nonthermal emissions in approximately the same proportion as major events. We discuss the distributions of flare parameters (e.g., peak flux) and how these parameters correlate, for instance via the Neupert effect. We also highlight the systematic biases involved in intercomparing data representing many decades of event magnitude. The intermittency of the flare/microflare occurrence, both in space and in time, argues that these discrete events do not explain general coronal heating, either in active regions or in the quiet Sun.



Copyright information

© Springer Science+Business Media B.V. 2011