Derived Electron Densities from Linear Polarization Observations of the Visible-Light Corona During the 14 December 2020 Total Solar Eclipse
Derived Electron Densities from Linear Polarization Observations of the Visible-Light Corona During the 14 December 2020 Total Solar Eclipse
复制标题
DOI：
10.1007/s11207-023-02231-5
复制
发表时间：
2023-10
期刊：
影响因子：
2.8
通讯作者：
Liam T. Edwards;Kaine A. Bunting;Brad Ramsey;Matt Gunn;Tomos Fearn;Thomas Knight;Gabriel D. Muro;Huw Morgan
中科院分区：
文献类型：
--
作者：
Liam T. Edwards;Kaine A. Bunting;Brad Ramsey;Matt Gunn;Tomos Fearn;Thomas Knight;Gabriel D. Muro;Huw Morgan
设计了一种新仪器，用于在2020年12月14日日全食期间对日冕进行可见光（VL）偏振亮度（）观测。该仪器被称为冠状成像偏振器（CIP），由一个16 MP CMOS探测器，一个安装在压电旋转支架内的线性偏振器和一个f-5.6，200 mm DSLR透镜组成。在恶劣的天气条件下，在线偏振器的六个不同取向角（、和）下，成功地获得了五种不同曝光时间（0.001 s、0.01 s、0.1 s、1 s和3 s）的观测结果。这些图像是利用天空中背景恒星的漂移手动对齐的，不同曝光时间的图像是利用简单的信噪比切割组合的。还估计了当地天空的偏振和亮度，并随后对观测结果进行了校正。K-日冕的大小是用最小二乘拟合确定的，辐射校准是相对于莫纳罗亚太阳天文台（MLSO）从日食当天的K-日冕观测完成的。然后对数据进行反演，获得赤道流和极日冕洞的日冕电子密度，这与之前的研究非常一致。还讨论了改变用于计算的偏振器角度的数量的影响，并且发现当使用所有六个偏振器角度与仅选择三个角度时，结果变化高达。
A new instrument was designed to take visible-light (VL) polarized brightness () observations of the solar corona during the 14 December 2020 total solar eclipse. The instrument, called theCoronal Imaging Polarizer(CIP), consisted of a 16 MP CMOS detector, a linear polarizer housed within a piezoelectric rotation mount, and an f-5.6, 200 mm DSLR lens. Observations were successfully obtained, despite poor weather conditions, for five different exposure times (0.001 s, 0.01 s, 0.1 s, 1 s, and 3 s) at six different orientation angles of the linear polarizer (,,,,, and). The images were manually aligned using the drift of background stars in the sky and images of different exposure times were combined using a simple signal-to-noise ratio cut. The polarization and brightness of the local sky were also estimated and the observations were subsequently corrected. Theof the K-corona was determined using least-squares fitting and radiometric calibration was done relative to theMauna Loa Solar Observatory(MLSO) K-Corobservations from the day of the eclipse. Thedata was then inverted to acquire the coronal electron density,, for an equatorial streamer and a polar coronal hole, which agreed very well with previous studies. The effect of changing the number of polarizer angles used to compute theis also discussed and it is found that the results vary by up towhen using all six polarizer angles versus only a select of three angles.