Characterizing motion types of G-band bright points in the quiet Sun*Supported by the National Natural Science Foundation of China. (April 2015)

• Record Type: Journal Article
• Authors: Yang, Yun-Fei; Qu, Hui-Xue; Ji, Kai-Fan; Feng, Song; Deng, Hui; Lin, Jia-Ben; Wang, Feng
• Is Part Of: Research in astronomy and astrophysics. Volume 15:Number 4(2015:Apr.)
• Page Start: 569
• Page End: 582
• Publication Date: 2015-04
• Subjects: Astronomy -- Periodicals; Astrophysics -- Periodicals; 520.5
• DOI: 10.1088/1674-4527/15/4/009
• Languages: English
• ISSNs: 1674-4527

Abstract

<abstract> <title>Abstract</title> <p>We study the motion of <italic>G</italic>-band bright points (GBPs) in the quiet Sun to obtain the characteristics of different motion types. A high resolution image sequence taken with the <italic>Hinode</italic>/Solar Optical Telescope (SOT) is used, and GBPs are automatically tracked by segmenting 3D evolutional structures in a space-time cube. After putting the GBPs that do not move during their lifetimes aside, the non-stationary GBPs are categorized into three types based on an index of their motion type. Most GBPs that move in straight or nearly straight lines are categorized as a straight motion type, a few moving in rotary paths into rotary motion, and the others fall into a motion type we called erratic. The mean horizontal velocities are 2.18±0.08 km s<sup>−1</sup>, 1.63±0.09 km s<sup>−1</sup> and 1.33±0.07 km s<sup>−1</sup> for straight, erratic and rotary motion types, respectively. We find that a GBP drifts at a higher and constant velocity during its whole life if it moves in a straight line. However, it has a lower and variational velocity if it moves on a rotary path. The diffusive process is ballistic-, super- and sub-diffusion for straight, erratic and rotary motion types, respectively. The corresponding diffusion index (γ) and coefficients (<italic>K</italic>) are 2.13±0.09 and 850±37 km<sup>2</sup> s<sup>−1</sup>, 1.82±0.07 and 331±24 km<sup>2</sup> s<sup>−1</sup>, and 0.73±0.19 and 13±9 km<sup>2</sup> s<sup>−1</sup>. In terms of direction of motion, it is homogeneous and isotropic, and usually persists between neighboring frames, no matter what motion type a GBP is classified as.</p> </abstract>