Document Details Document Type : Article In Journal  Document Title : FLARE DEVELOPMENT IN ACTIVE-REGION NOAA-6891, 30 OCTOBER, 1991 FLARE DEVELOPMENT IN ACTIVE-REGION NOAA-6891, 30 OCTOBER, 1991   Document Language : Arabic  Abstract : A great sunspot group of October 1991 (NOAA 6891 at L = 189, B = -10) was observed, in which an eruptive flare of importance (X2.5/3B) has been reported. A Ca II-line 3933 Angstrom filter was used, and during a time interval of 3 hours more than 90 frames were taken, using a CCD camera. The progress and the distribution in size of the two main flare points have been obtained; they covered an area of about 1800 millionths of the solar disk within a time interval of about 24 min. The average apparent horizontal velocity was 70 km s(-1).  Journal Name : SOLAR PHYSICS  Volume : 158  Issue Number : 2  Publishing Year : 1995 AH   Added Date : Monday, June 16, 2008  Researchers Researcher Name (Arabic) Researcher Name (English) Researcher Type Dr Grade Email حسن بن محمد حسين باصرة   Researcher     عبدالرحمن بن علي سعيد ملاوي   Researcher     فـؤاد بن يوســف كمـال   Researcher     ياسين بن محمد أحمد المليكي   Researcher     Back To Researches Page