Umbral Fine Structures in Sunspots Observed with Hinode Solar Optical Telescope
Abstract
High resolution imaging observation of a sunspot umbra was done with Hinode Solar Optical Telescope (SOT). Filtergrams in wavelengths of blue and green continuum were taken during three consecutive days. The umbra consisted of a dark core region, several diffuse components and numerous umbral dots. We derived basic properties of umbral dots (UDs), especially their temperatures, lifetimes, proper motions, spatial distribution and morphological evolution. Brightness of UDs is confirmed to depend on the brightness of their surrounding background. Several UDs show fission and fusion. Thanks to the stable condition of space observation, we could first follow the temporal behavior of these events. The derived properties of internal structure of the umbra are discussed in viewpoint of magnetoconvection in a strong magnetic field.
Cite
@article{arxiv.0711.3266,
title = {Umbral Fine Structures in Sunspots Observed with Hinode Solar Optical Telescope},
author = {Reizaburo Kitai and Hiroko Watanabe and Tahei Nakamura and Ken-ichi Otsuji and Takuma Matsumoto and Satoru UeNo and Shin-ichi Nagata and Kazunari Shibata and Richard Muller and Kiyoshi Ichimoto and Saku Tsuneta and Yoshinori Suematsu and Yukio Katsukawa and Toshifumi Shimizu and Theodore D. Tarbell and Richard A. Shine and Alan M. Title and Bruce W. Lites},
journal= {arXiv preprint arXiv:0711.3266},
year = {2015}
}
Comments
6 pages, 8 figures, accepted for publication in PASJ (Hinode Special Issue)