Date of Award
Master of Science (MS)
Paul S. Hardersen
Sara F. Martin
This thesis focuses on identifying the mechanism by which solar filaments acquire mass. Some of the speculations for how a filament gets its mass are 1) injection of mass from the chromosphere into the filament structure, and 2) condensation of mass from the corona into the region of the filament channel. Mass motion at the footpoints of the filaments is studied to detect mass entering and leaving the filament body. The magnetic properties of the footpoints of the filaments are also studied. Recommendations are drawn by comparing observational properties obtained in this study with the features used in some of the previously developed models.
The datasets used for this study are high-resolution image sets of centerline and Doppler wings of H⍺, obtained using the Dutch Open Telescope (DOT). The data were obtained on Oct 30, 2010. The data set contains three filaments in an active region in the northern hemisphere of the Sun. The images in each wavelength are aligned and made into movies to find the footpoints of the filaments through which the mass goes into and comes out of the filaments from and to the chromosphere, respectively. The magnetic properties of the footpoints are studied by overlaying the magnetogram images with the DOT images by using full-disk H⍺ images for matching the features in the two.
Of the three filaments, one of the filaments is observed to be stable throughout the duration of the observations; another filament erupts after about two hours of the beginning of observations; and the third filament is in its early stages of formation. The ends of the stable filament are clearly observed whereas the ends of the erupting filament and the forming filament are observed clearly intermittently during the duration of the observations.
The animations of the region near the ends of filament 1 reveal definite injection and draining of mass via the footpoints into and out of the filament. The mass motion into and out of the filaments are observed to be comparable with that occurring in chromospheric fibrils. Of the total number of footpoints observed, a majority of them appear to be rooted on or on the borders of the majority polarities of the active region.
Venkataramanasastry, Aparna, "The Structures, Mass Motions And Footpoints Of Solar Filaments" (2014). Theses and Dissertations. 1604.