Astronomy Picture of the Day
探索宇宙！每天一幅不同的影像或照片，并由专业天文学家的简短解释和说明，带你遨游迷人的宇宙。
2006年4月16日（农历二〇〇六年三月十九）
http://www.phys.ncku.edu.tw/%7Ea ... noxprom_eit_big.jpg
SOHO 卫星的日珥
影像提供: SOHO-EIT Consortium, ESA, NASA
Explanation: How can gas float above the Sun? Twisted magnetic fields arching from the solar surface can trap ionized gas, suspending it in huge looping structures. These majestic pl
arches are seen as prominences above the solar limb. In September 1999, this dramatic and detailed image was recorded by the EIT experiment on board the space-based SOHO observatory in the light emitted by ionized Helium. It shows hot pl escaping into space as a fiery prominence breaks free from magnetic confinement a hundred thousand kilometers above the Sun. These awesome events bear watching as they can affect communications and power systems over 100 million kilometers away on Planet Earth.解释：气体为何漂浮在太阳上空？太阳表面拱形的扭曲的磁场可以困住电离气体,阻止其形成巨大的环形结构. 当这些壮丽的等离子体拱环出现在太阳边缘时，就形成日珥。1999年9月，这一激动人心而又详细的情景被SOHO空间天文台上的远紫外光相机通过电离氢的波段记录下来。它呈现了一个狂暴的日珥挣脱磁场的束缚冲到数十万公里高空时，炽热电浆脱离太阳进入太空的情景。我们必需注意这种壮观的事件，因为它们可能会影响到一亿公里外地球上的通讯和电力系统。