2026-09-30 国立天文台
今回の観測で捉えられた静穏領域の上空にある磁場（右の正方形）と、数値シミュレーションで再現された磁場構造（左の正方形）。観測が捉えた細い糸のような磁場構造が、数値シミュレーションではねじれた磁力線（左下の円内の拡大図）として再現されています。（クレジット：NAOJ / MPS / Sunrise-III/SCIP）
＜関連情報＞
- https://www.nao.ac.jp/news/science/2026/20260930-sso.html
- https://iopscience.iop.org/article/10.3847/2041-8213/ae909b
SUNRISE III/SCIPによって明らかになった静穏太陽領域の三次元磁場構造 Three-dimensional Magnetic Field Structure of a Quiet-Sun Region Revealed by SUNRISE III/SCIP
Masahito Kubo, Yukio Katsukawa, Yusuke Kawabata, Takayoshi Oba, Hirohisa Hara, Toshifumi Shimizu, Ryohtaroh T. Ishikawa, Takuma Matsumoto, Yoshihiro Naito, Fumihiro Uraguchi,…
The Astrophysical Journal Letters Published: 2026 August 26
DOI:10.3847/2041-8213/ae909b
Abstract
The balloon-borne stratospheric solar observatory Sunrise iii successfully completed 6.5 days of observations in 2024 July. One of its focal-plane instruments, the Sunrise Chromospheric Infrared spectroPolarimeter (SCIP), is a slit-scanning spectropolarimeter that simultaneously measures full Stokes profiles of multiple spectral lines in the 850 nm and 770 nm bands. SCIP obtained an unprecedented data set of a quiet-Sun region near the disk center, covering a 58″ × 58″ field of view. With an integration time of 10 s per slit position, the scan was completed in 107 minutes without interruption, achieving remarkably stable polarimetric precision of 0.03%–0.04% (1σ) of the continuum level. The multiwavelength SCIP observations reveal that the chromospheric line-of-sight (LOS) magnetic field exhibits thread-like elongated structures over the internetwork regions, with no obvious photospheric counterpart directly below. These threads are typically narrower than 1″ and are embedded within the canopy fields extending from the network regions. Their LOS field strengths derived from the weak-field approximation are typically 10–20 G weaker than the surrounding canopy. In particularly clear cases, the magnetic polarity of the threads is opposite to that of the adjacent canopy. These findings suggest that the canopy field is not simply an expanding structure originating from network regions, but instead has a complex three-dimensional configuration containing numerous localized substructures. These observations provide new constraints on the quiet-Sun magnetic topology from the photosphere to the chromosphere.
