Solar Flares

太阳耀斑

While sunspots are relatively cool and quiescent regions on the Sun, the photosphere around them sometimes erupts with outflows of high energy particles in active regions. Most often these eruptions are in the form of loops and sheets called prominences, but there are other events which in a matter of minutes can release enormous amounts of energy and eject material out into space. Such violent events are called solar flares.

尽管太阳黑子是太阳上相对较冷且平静的区域，但它们周围的光球层有时会爆发高能粒子的喷流，在活跃区域中发生。这些爆发大多数表现为称为日冕的环形和片状结构，但也有其他事件，在几分钟内可以释放出巨大的能量并将物质喷射到空间中。这类剧烈事件被称为日冕爆发。

Solar flares are associated with the magnetic activity of the Sun. The most energetic of the observed solar flares is called the Carrington event which occurred on September 1, 1859. It had an estimated energy around 10³² ergs. This is equal to 10²⁵ Joules or about a hundred million megatons of TNT!. The Kepler satellite has enabled us to detect a number of superflares from stars in the solar neighborhood, which may have energies 10,000 times that of the Carrington event.

日冕爆发与太阳的磁活动有关。观测到的最强烈的日冕爆发被称为卡林顿事件，发生在1859年9月1日。其估计能量约为10³²尔格。这相当于10²⁵焦耳，或约一百万万吨TNT！开普勒卫星使我们能够检测到太阳邻近恒星上的若干超爆发，其能量可能达到卡林顿事件的10,000倍。

"The Carrington Event caused strong auroral displays and wrought havoc with telegraph systems. A solar storm of this magnitude occurring today would cause widespread electrical disruptions, blackouts and damage due to extended outages of the electrical grid.The solar storm of 2012 was of similar magnitude, but it passed Earth's orbit without striking the planet, missing by nine days. "(Wiki)

卡林顿事件导致了强烈的极光现象，并对电报系统造成了严重破坏。如果今天发生如此规模的太阳风暴，将导致广泛的电力中断、停电和损害，因为电力 grid 会因长时间停电而受损。2012年的太阳风暴规模相似，但其轨迹使它在地球轨道上绕行而未击中地球，比地球轨道偏离了九天。

Solar Prominences

日冕

This is a NASA image of a huge solar prominence on September 29, 2008, obtained as a part of the STEREO Project. The data was taken at a wavelength of 304 nm in the ultraviolet. The event rose over a period of several hours like a flag unfurling and then broke apart and headed into space. The material involved is ionized helium at about 60,000 Kelvin. The size of this prominence is many times the size of the Earth, as can be seen in a relative scale image of the Earth and Sun.

这是一张2008年9月29日由NASA拍摄的巨大的日冕物质抛射图像，属于STEREO项目的一部分。数据是在紫外波段304纳米取得的。事件持续数小时，如同旗帜展开般升起，随后破裂并进入空间。所涉及的物质是约60000开尔文的电离氦。这个日冕物质抛射的规模是地球的许多倍，这可以从地球与太阳的相对尺度图像中看到。

While sunspots are relatively cool and quiescent regions on the Sun, the photosphere around them sometimes erupts with outflows of high energy particles in active regions. Most often these eruptions are in the form of loops and sheets called prominences which remain under the control of the intense magnetic fields associated with solar storms. There are other events which in a matter of minutes can release enormous amounts of energy and eject material out into space. Such violent events are called solar flares.

尽管太阳黑子是太阳上相对较冷且平静的区域，但它们周围的光球层有时会爆发高能粒子的喷射，尤其是在活跃区域。这些爆发通常以称为日冕的环形和片状结构形式出现，这些结构仍受与太阳风暴相关的强磁场控制。还有其他事件，可在几分钟内释放出巨大的能量，并将物质喷射到空间中。这类剧烈事件被称为日冕爆发。

Solar prominences are typically observed to be high loops of hot ionized gases which follow the geometry of the magnetic fields associated with pairs of sunspots. According to Chaisson & McMillan, the size of a typical solar prominence is on the order of 100,000 km or around 10 times the diameter of Earth. Larger ones can reach a half-million kilometers. Prominences can show surges in time scales of hours, but the quiescent ones can persist for days or weeks. The energy release of the largest prominences can be on the order of 10²⁵ joules, compared to a total energy release of the Sun on the order of 10²⁶ joules/sec.

太阳日冕通常被观测到是高温电离气体的高架环，它们遵循与日珥对的太阳黑子相关的磁场的几何形状。根据Chaisson & McMillan的说法，典型日冕的尺寸大约为100,000公里，或约为地球直径的10倍。更大的日冕可以达到五十万公里。日冕可以在小时尺度上出现突增，但平静的日冕可以持续数天或数周。最大日冕的能量释放大约为10²⁵焦耳，相比之下，太阳的总能量释放约为10²⁶焦耳/秒。

This NASA image shows the looping structure of the ionized gases of prominences as controlled by the magnetic fields of the sunspot pairs.

这张NASA图片显示了日珥中带电气体的环状结构，这种结构由日冕中双极磁区域的磁场所控制。

A more isolated prominence shows the looping geometry.

更孤立的日冕显示出环状几何结构