Date of Award
Master of Science (MS)
Two spectral lines are often used to observe solar prominences: Hα and He II 304 Å. Both emission lines capture the same prominence structure but at vastly different temperatures: Hα is visible at ~10,000K while He II 304 Å. at ~80,000K. The He II 304 Å images provide the ability to identify the relatively hotter outer region of a prominence, although they lack the details seen in the cooler lower regions. Hα conversely shows great detail in the cooler lower regions of a prominence but lack any detail in the hotter outer region of a prominence. Two prominences will be the subject of this paper, a low lying prominence on the northeast limb of the Sun and a larger prominence near an active region on the northwest limb of the Sun. Analysis of simultaneous images of prominences using the SDO's Atmospheric Imaging Assembly (AIA) at the He II 304 Å wavelength and the Dutch Open Telescope (DOT) Hα wavelength reveal both similar and different morphology. The challenge when comparing observations from both systems is to obtain sufficient congruence to determine the prominence properties and structure.
Hα images tend to show the cooler core of a prominence and detail in the finer structure. 304 Å images show much more detail in the terms of higher hotter material which gives a greater sense to the structure and life of a prominence. By studying both wavelengths a more complete picture of the properties, structure and the evolution of a prominence can be learned.
Schiralli, Jonathan, "A Comparison Of Solar Prominence Data Between Hα And EUV (he II-304Å)" (2014). Theses and Dissertations. 1592.