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Statistical Characteristics of CMEs and Flares Associated with Solar Type II Radio Bursts
Authors:Shanmugaraju  A  Moon  Y-J  Dryer  M  Umapathy  S
Institution:(1) San Fernando Observatory, Department of Physics and Astronomy, California State University, Northridge, Northridge, CA, 91330-8268, U.S.A
Abstract:We present results from a study of sunspots and faculae on continuum and Cathinspii K images taken at the San Fernando Observatory (SFO) during 1989–1992; a total of approximately 800 images in each bandpass were used. About 18thinsp000 red sunspots, 147thinsp000 red faculae, and 800thinsp000 Cathinspii K faculae were identified based on their contrasts. In addition, we computed the contrasts of pixels on the red images cospatial with Cathinspii K faculae. Sunspot contrasts show a strong dependence on size but no dependence on heliocentric angle. There are continuous but systematic differences among facular regions. We find that the contrast of Cathinspii K faculae is relatively insensitive to heliocentric angle, but is a strong function of facular size, in the sense that larger Cathinspii K faculae are always brighter. The contrast of red faculae is a function of both heliocentric angle and size: the contrast functions show that larger regions contain larger flux tubes, contain deeper flux tubes, and have larger filling factors than small facular regions. Comparisons of cospatial pixels on red and Cathinspii K images show a tight correlation between the average contrast of a region in the continuum and its size and heliocentric angle in the Cathinspii K images. The average contrast of all facular regions is positive everywhere on the disk, even though the largest regions contain flux tubes which appear dark at disk center.
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