• Magnetic and Velocity Field Variations in the Active Regions NOAA 10486 and NOAA 10488

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      https://www.ias.ac.in/article/fulltext/joaa/029/01-02/0103-0105

    • Keywords

       

      Sun: magnetogram; Sun: Dopplergram; Sun: flare.

    • Abstract

       

      We study the magnetic and velocity field evolution in the two magnetically complex active regions NOAA 10486 and NOAA 10488 observed during October–November 2003.We have used the available data to examine net flux and Doppler velocity time profiles to identify changes associated with evolutionary and transient phenomena. In particular, we report detection of rapid moving features observed in NOAA 10486 during the maximum phase of the X17.2/4B superflare of October 28, 2003. The velocity of this moving feature is estimated around 40 km/s, i.e., much greater than the usual H𝛼 flare-ribbons’ separation speed of 3–10 km/s, but similar to the velocity of seismic waves, i.e., ∼ 45 km/s reported earlier by Kosovichev & Zharkova (1998).

    • Author Affiliations

       

      Ram Ajor Maurya1 Ashok Ambastha1

      1. Udaipur Solar Observatory, Physical Research Laboratory, P. O. Box 198, Dewali, Badi Road, Udaipur 313 001, India.
    • Dates

       
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