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Solar Physics

, Volume 262, Issue 2, pp 321–335 | Cite as

Solar Cycle 23 in Coronal Bright Points

  • Isroil Sattarov
  • Alexei A. PevtsovEmail author
  • Nina V. Karachik
  • Chori T. Sherdanov
  • A. M. Tillaboev
Solar Image Processing and Analysis

Abstract

We describe an automatic routine to identify coronal bright points (CBPs) and apply this routine to SOHO/EIT observations taken in the 195 Å spectral range during solar cycle 23. We examine the total number of CBPs and its change in the course of this solar cycle. Unlike some other recent studies, we do find a modest ≈30% decrease in the number of CBPs associated with maximum of sunspot activity. Using the maximum brightness of CBPs as a criterion, we separate them on two categories: dim CBPs, associated with areas of a quiet Sun, and bright CBPs, associated with an active Sun. We find that the number of dim coronal bright points decreases at the maximum of sunspot cycle, while the number of bright CBPs increases. The latitudinal distributions suggest that dim CBPs are distributed uniformly over the solar disk. Active Sun CBPs exhibit a well-defined two-hump latitudinal profile suggestive of enhanced production of this type of CBPs in sunspot activity belts. Finally, we investigate the relative role of two mechanisms in cycle variations of CBP number, and conclude that a change in fraction of solar surface occupied by the quiet Sun’s magnetic field is the primary cause, with the visibility effect playing a secondary role.

Keywords

Instrumentation and data management Solar corona, structures Solar cycle 

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Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Isroil Sattarov
    • 1
  • Alexei A. Pevtsov
    • 2
    Email author
  • Nina V. Karachik
    • 2
  • Chori T. Sherdanov
    • 3
  • A. M. Tillaboev
    • 1
  1. 1.Tashkent State Pedagogical UniversityTashkentUzbekistan
  2. 2.National Solar ObservatorySunspotUSA
  3. 3.Astronomical Institute AS of UzbekistanTashkentUzbekistan

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