Clara Yono Yatini
National Institute of Aeronautics and Space (LAPAN)

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Analysis of the Proper Motion of Sunspots before the Flare Onset on NOAA 0375 and NOAA 9715 Clara Yono Yatini; Rasdewita Kesumaningrum; Santi Sulistiani
Jurnal Matematika & Sains Vol 12, No 2 (2007)
Publisher : Institut Teknologi Bandung

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Abstract

We have examined the movements of individual sunspots within two sunspot groups, NOAA 0375 in association with M7.3 flare appeared on 12 June 2003 and NOAA 9715 associated with M1.3 flare on 2 December 2001. For this purpose we measured the distance of two bipolar spots directly related to the flares with respect to a reference spot in the active region during the period before flare activity and estimated the average velocity of their movements. The main result is that the spots related with flares had average velocity greater than the flare-unrelated spots.
Measurement of Sunspot Proper Motion Using Cross-Correlation Method Clara Yono Yatini; Soshinori Suematsu; Emanuel Sungging Mumpuni
Jurnal Matematika & Sains Vol 8, No 3 (2003)
Publisher : Institut Teknologi Bandung

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Abstract

Cross-correlation method is a technique for determining the vector displacement that maximizes the spatially local cross-correlation between an image and a reference image as a continuous function of the image space. The crosscorrelation is defined as a function of position in the image, within a spatially localized apodization window. This method is applied to measure the proper motion of the sunspot accurately which can be calculated from a series of active region images as a function of time. This method gives a measure of the spot displacement unaffected by the jitter of the telescope.