印度首个太阳观测卫星Aditya-L1的最新研究成果为太阳日冕为何能达到极高温度这一长期谜团提供了重要线索[1]。由印度天体物理研究所拉梅什教授领导的研究发现，日冕能量补充的93%源于磁场线的断裂与重新连接，而仅有7%来自太阳表面的波动运动[1]。这一发现解释了日冕如何在频繁释放能量后仍能维持约200万摄氏度（有时可达4000万摄氏度）的极高温度——相比之下，太阳表面温度仅约5500摄氏度[1]。
研究团队通过Aditya-L1卫星搭载的Velc日冕仪观测了2024年8月5日发生的一次"非常活跃的"日冕质量抛射事件[1]。数据显示，日冕质量抛射发生后，磁场线在10小时内完成恢复和重新配置[1]。这项研究已在权威的《天体物理学杂志快报》上发表[1]。值得注意的是，太阳目前正处于每11年一个周期的活动高峰期，此时日冕质量抛射事件会显著增加，从正常情况下每天2-3次增至每天10次以上[1]。
India's Aditya-L1 solar observatory has provided significant clues about one of astronomy's enduring puzzles: why the Sun's corona reaches temperatures millions of degrees higher than its surface.[1] Research led by Professor Ramesh of the Indian Institute of Astrophysics found that magnetic field reconnection accounts for 93 percent of the coronal energy replenishment, while surface wave motion contributes only 7 percent.[1] This finding explains how the corona sustains such extreme temperatures even after frequently releasing energy.
The study examined an exceptionally active coronal mass ejection that occurred on August 5, 2024, observed using the Velc coronagraph aboard Aditya-L1.[1] Within 10 hours following the coronal mass ejection, magnetic field lines restored and reconfigured themselves, demonstrating the rapid energy recovery mechanism.[1] The research reveals a striking contrast: while the Sun's core reaches 15 million degrees Celsius and its surface around 5,500 degrees Celsius, the corona typically maintains approximately 2 million degrees Celsius, occasionally surging to 40 million degrees.[1] The findings, published in the prestigious Astrophysical Journal Letters, show that the frequency of such eruptions varies significantly with the solar cycle—occurring 2 to 3 times daily under normal conditions but exceeding 10 times daily during the maximum activity phase of the Sun's 11-year cycle.[1]