We investigate the evolutionary effects on the brightness of a sunspot as well as on the properties of its fine-structures using two sets of time series of G-band images of a single sunspot in NOAA 10944 recorded at two symmetric locations on the solar disc by Hinode/SOT (Solar Optical Telescope). The second time series (phase W) was recorded 2.5 d after recording the first time series (phase E). Both time series of images were corrected for instrumental stray light; then the p-mode oscillations were removed. Our analysis demonstrates that the spatially and temporally averaged intensities of the umbra as well as the penumbra in both phases are practically the same. Nevertheless, considering only intensities smaller than 1.0 I ph $\mbox{I}_{\mathrm{ph}}$ the penumbra in the phase W is brighter with a contrast of 2 per cent. However, the ratio of the peak intensities of penumbral grains to their background intensities decreases, on average, from 2.9 to 2.6 from phase E to phase W. The penumbra is on average, 6.9 times brighter than the umbra in both phases. The umbra gets smaller in size with a ratio of 0.90 and its magnetic field strength decreases about 200 G after the 2.5 d evolution. Although the central umbral dots (UDs) with lifetimes longer than 2 min are by the factor of 1.6 more frequent in phase E, the most of the physical and kinematic properties of UDs do not show considerable changes after the sunspot evolution at this 2.5 d time interval. The registered UDs have intensities smaller than 0.84 I ph $\mbox{I}_{\mathrm{ph}}$ with a mean intensity of about 0.29 I ph $\mbox{I}_{\mathrm{ph}}$ . The equivalent diameters of the individual UDs have a symmetric distribution around 180 km with a standard deviation about 35 km. The brightest UDs show a constant median diameter. The UDs registered in both phases have a mean lifetime of 7.4 min. Our results suggest that UDs with a certain lifetime have an admissible lower limit for their mean size which grows with lifetime. The proper motions of UDs show velocities less than 1.0 km s − 1 $1.0~\mbox{km}\,\mbox{s}^{-1}$ with a maximum population around 0.2 km s − 1 $0.2~\mbox{km}\,\mbox{s}^{-1}$ . The UDs formed in the phase W are faster when the umbral area is smaller and the magnetic field is weaker.

中文翻译：

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两个不同时间点的太阳黑子比较研究

我们使用 NOAA 10944 中单个太阳黑子在太阳盘上两个对称位置记录的两组时间序列 G 波段图像研究了对太阳黑子亮度及其精细结构性质的演化影响Hinode/SOT（太阳光学望远镜）。在记录第一个时间序列（阶段 E）后 2.5 天记录第二个时间序列（阶段 W）。两个时间序列的图像都针对仪器杂散光进行了校正；然后消除了 p 模式振荡。我们的分析表明，两个阶段中本影和半影的空间和时间平均强度实际上是相同的。然而，仅考虑小于 1.0 I ph $\mbox{I}_{\mathrm{ph}}$ 的强度，W 相中的半影更亮，对比度为 2%。然而，从 E 相到 W 相，半影颗粒的峰值强度与其背景强度之比平均从 2.9 降低到 2.6。半影平均比两相中的本影亮 6.9 倍。2.5 d 演化后，本影尺寸变小，比例为 0.90，磁场强度下降约 200 G。尽管寿命超过 2 分钟的中央本影点（UDs）在 E 相中的频率高出 1.6 倍，但在这 2.5 d 时间的太阳黑子演化之后，UDs 的大部分物理和运动学特性并未表现出相当大的变化间隔。注册的 UD 的强度小于 0.84 I ph $\mbox{I}_{\mathrm{ph}}$ ，平均强度约为 0.29 I ph $\mbox{I}_{\mathrm{ph}}$ 。单个 UD 的等效直径在 180 公里左右对称分布，标准偏差约为 35 公里。最亮的 UD 显示出恒定的中值直径。在两个阶段注册的 UD 的平均寿命为 7.4 分钟。我们的结果表明，具有特定寿命的 UD 的平均尺寸有一个可接受的下限，该下限随寿命而增长。UDs 的自行显示速度小于 1.0 km s − 1 $1.0~\mbox{km}\,\mbox{s}^{-1}$，最大种群在 0.2 km s − 1 $0.2~\mbox{km }\,\mbox{s}^{-1}$ 。当本影区域较小且磁场较弱时，W 相中形成的 UD 速度较快。我们的结果表明，具有特定寿命的 UD 的平均尺寸有一个可接受的下限，该下限随寿命而增长。UDs 的自行显示速度小于 1.0 km s − 1 $1.0~\mbox{km}\,\mbox{s}^{-1}$，最大种群在 0.2 km s − 1 $0.2~\mbox{km }\,\mbox{s}^{-1}$ 。当本影区域较小且磁场较弱时，W 相中形成的 UD 速度较快。我们的结果表明，具有特定寿命的 UD 的平均尺寸有一个可接受的下限，该下限随寿命而增长。UDs 的自行显示速度小于 1.0 km s − 1 $1.0~\mbox{km}\,\mbox{s}^{-1}$，最大种群在 0.2 km s − 1 $0.2~\mbox{km }\,\mbox{s}^{-1}$ 。当本影区域较小且磁场较弱时，W 相中形成的 UD 速度较快。