Solar Physics

, Volume 138, Issue 1, pp 205–208 | Cite as

Study of periodicities of solar nuclear gamma ray flares and sunspots

  • V. K. Verma
  • G. C. Joshi
  • D. C. Paliwal
Solarphysics Letters


Here we have carried out a power-spectrum analysis of solar nuclear gamma-ray (NGR) flares observed by SMM and HINOTORI satellites. The solar NGR flares show a periodicity of 152 days, confirming the existence of a 152–158 days periodicity in the occurrence of solar activity phenomena and also indicating that the NGR flares are a separate class of solar flares. The power-spectrum analysis of the daily sunspot areas on the Sun for the period 1980–1982 shows a peak around 159 days while sunspot number data do not show any periodicity (Verma and Joshi, 1987). Therefore, only sunspot area data should be treated as an indicator of solar activity and not the daily sunspot number data.


Flare Solar Activity Solar Flare Sunspot Number Sunspot Area 
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Copyright information

© Kluwer Academic Publishers 1992

Authors and Affiliations

  • V. K. Verma
    • 1
  • G. C. Joshi
    • 1
  • D. C. Paliwal
    • 1
  1. 1.Uttar Pradesh State ObservatoryManora Peak, Naini TalIndia

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