Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8133394 | Chinese Astronomy and Astrophysics | 2016 | 15 Pages |
Abstract
Photospheric bright points (PBPs) are tiny short-lived brightening phenomena that can be seen within dark inter-granular lanes. In this paper, we develop a new method to identify and track a PBP in a 3D space-time cube. Different from the common-adopted strategy of “identifying-before-tracking”, this algorithm is based on the strategy of “identifying-by-tracking”. This method can identify a PBP when its intensity is still rather weak, and can avoid the discontinuous evolution of PBP caused by the algorithm of Laplacian morphological dilation (LMD) to recognize completely the evolutionary process of a PBP. The statistics on a group of G-band data observed by Hinode/SOT (Solar Optical Telescope) in quiet regions indicate that the average lifetime of isolated PBP is as long as 3Â minutes, and the longest lifetime is up to 27Â minutes, which means that the lifetime of PBPs is longer than that obtained by the previous LMD algorithm. Furthermore, it is also found that the mean intensity contrast of PBPs is 1.02 times of the mean photospheric intensity, which is weaker than that calculated by the LMD algorithm, and that the intensity of PBP exhibits a periodical oscillation of 2â¼3Â minute during the whole lifetime.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
Xiong Jian-ping, Zhang Ai-li, Ji Kai-fan, Feng Song, Deng Hui, Yang Yun-fei,