Record Prominence Imaged by Solar Orbiter
Image Credit: Solar Orbiter, EUI Team, ESA & NASA; h/t: Bum-Suk Yeom
Explanation: What’s happened to our Sun? Last month, it produced the largest prominence ever imaged together with a complete solar disk. The record image, featured, was captured in ultraviolet light by the Sun-orbiting Solar Orbiter spacecraft. A quiescent solar prominence is a cloud of hot gas held above the Sun’s surface by the Sun’s magnetic field. This solar prominence was huge — spanning a length rivaling the diameter of the Sun itself. Solar prominences may erupt unpredictably and expel hot gas into the Solar System via a Coronal Mass Ejection (CME). When a CME strikes the Earth and its magnetosphere, bright auroras may occur. This prominence did produce a CME, but it was directed well away from the Earth. Although surely related to the Sun’s changing magnetic field, the energy mechanism that creates and sustains a solar prominence remains a topic of research.
Tomorrow’s picture: spiral galaxy NGC 2841
太阳轨道飞行器拍摄的创纪录日珥
影像提供: Solar Orbiter, EUI Team, ESA & NASA; h/t: Bum-Suk Yeom
说明: 太阳发生了什么事？上个月，它产生一个影像记录史上最庞大的日珥 ，而同时入镜的还有完整的日盘。上面这幅呈现此创纪录日珥的主题影像，是由绕行太阳的太阳轨道飞行器拍摄于紫外光波段。太阳表面上方的宁静日珥，是指受太阳磁场局束的悬浮团状炽热气体。上图的日珥极为庞大，其宽度和太阳的直径相当。日珥有时会突然发生爆发，并以日冕物质抛射（CME）的形式，把炽热气体喷入太阳系。当日冕物质抛射冲撞地球及其磁层时，有时会触发明亮的极光。这例日珥后来的确产生日冕物质抛射，但喷发在远离地球的方向。虽然日珥和太阳多变的磁场必然有关联，不过日珥到底如何形成和维持，其能量机制仍然是科学研究的课题。
明日的图片: spiral galaxy NGC 2841
