SOHO CoRoT Kepler Picard SDO GONG

Analysis of peculiar penumbral flows in the NOAA active region 10930 during a major solar flare


Kumar Brajesh


Udaipur Solar Observatory / Physical Research Labo


Local helioseismology
Auteur(s) supplémentaire(s)P. Venkatakrishnan(1), Savita Mathur(2), Sanjiv Kumar Tiwari(1), and R. A. Garcia(3)
Institution(s) supplémentaire(s)(1). Udaipur Solar Observatory, PRL, Dewali, Badi Road, Udaipur 313 004 INDIA (2) High Altitude Observatory, Boulder, CO 80302, USA (3). Laboratoire AIM, CEA/DSM-CNRS, IRFU/Sap, FRANCE.


During the solar minimum phase between activity cycles 23 and 24, a complex active region NOAA 10930 gave rise to a major flare (of class X3.4) on 13 December 2006 during its passage on the solar disk. The photospheric observations taken in Ca II H and G-band by Solar Optical Telescope (SOT) on board Hinode satellite have shown elongated flare ribbons which separate apart with the progress of the flare. The hard X-ray (HXR) images obtained by RHESSI satellite show double-footpoint HXR sources located on the flare ribbons. There are also reports on the lateral motion of penumbral filaments in this active region during the flare. Motivated by the aforementioned examples, we have analyzed the velocity flows in different parts of this active region (AR) during the flare using the Dopplergrams obtained by the GONG telescope. We observe peculiar evolution of velocity flows in some localized portions of the penumbra of this AR during the flare. The aforementioned localized penumbral parts are observed to be located on the flare ribbon. In this paper, we will present the results obtained by the Wavelet and Fourier analyzes of these penumbral velocity flows observed during this major solar flare. Also, we will present the results related to flare induced changes in the global velocity oscillations of the Sun as observed with GOLF instrument on board SOHO satellite.
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