2026-06-08 中国科学院（CAS）
◆研究では、新真空太陽望遠鏡（NVST）の高分解能観測データを用いて6例のLBジェットを解析した。その結果、ジェット基部（JBP）がライトブリッジに沿って滑るように移動し、その後に細長いジェット本体も同様の運動を示すことが確認された。また、中国の太陽観測衛星CHASEの分光データから、ジェット基部で磁気リコネクションが発生していることを示すエラーマンボム様のスペクトル特性が検出された。研究チームは、ライトブリッジ内の比較的水平な磁場と周囲の暗部（アンブラ）の強い鉛直磁場との間で三次元的な「スリッピング磁気リコネクション」が繰り返し起こり、ジェットを駆動していると結論づけた。この過程は、対流上昇流や磁束輸送によって生じる光球面の周期的な水平運動によって誘発または変調されると考えられる。
◆今回の成果は、ライトブリッジジェットとコロナジェットの共通した発生機構を示すとともに、太陽大気中での三次元磁気リコネクションの直接的な観測証拠を提供した。
A)-(F) Zoomed-in snapshots showing the evolution of an LB jet from 02:41 UT to 02:50 UT in NVST TiO, Ha -0.6 Å, AIA 1600 Å, 171 Å images and Doppler proxy maps. The black arrows and the cyan circles in panels (A) and (B) denote a horizontal motion front along the light bridge. The white and black arrows in panel (C)-(E) point out the bright footpoints at the base of the LB jet. The red circle marks the bright plasma moving along the leading edge of the LB jet. The green Ha curve at the selected point in panel (h) is marked with a green diamond symbol in (e). (Image by DUAN Yadan)
＜関連情報＞
- https://english.cas.cn/newsroom/research-news/202606/t20260608_1161390.shtml
- https://iopscience.iop.org/article/10.3847/2041-8213/ae6340
太陽黒点の光橋ジェットの繰り返し発生と、それに伴う基底部の輝度低下 Repeated Sunspot Light Bridge Jets Associated with Slipping Base Brightenings
Yadan Duan, Xiaoli Yan, Yuhang Gao, Jincheng Wang, Zhe Xu, and Yongyuan Xiang
The astrophysical Journal Letters Published: 2026 May 13
DOI:10.3847/2041-8213/ae6340
Abstract
Light bridge (LB) jets offer a unique window into small-scale eruptive phenomena within sunspots, the Sun’s strongest magnetic environments; however, their generation mechanism remains a subject of debate. Using high-resolution observations from the New Vacuum Solar Telescope, we investigated six recurrent LB jets and the slipping motions of their jet base points (JBPs). Analogous to coronal jets, our observations show that these LB jets are characterized by a preceding JBP followed by a collimated jet spire. The JBP of each repeated jet along the LB displays apparent slipping motion at velocities of 0.6–1.5 km s−1, which is temporally correlated with a quasiperiodic enhanced photospheric horizontal motion of 1.3–6.5 km s−1. Following the slipping JBPs, the resulting jet spires’ fronts display similar slipping behaviors within the upper solar atmosphere. The Chinese Hα Solar Explorer reveals Ellerman-bomb-like spectral signatures at the JBPs, confirming that magnetic reconnection is operating at the jet base. Based on these results, we propose that repeated 3D reconnection occurring between the horizontal LB field and the ambient vertical umbral field may drive these LB jets. This process appears to be driven and/or modulated by quasiperiodic horizontal motion fueled by convective upflows and the transport of magnetic flux along the LB. This work suggests that some LB jets share a common reconnection-driven mechanism with coronal jets and provides direct evidence of slipping reconnection occurring along the sunspot LB.
