Silversun

Silversun ejection

A silversun ejection (SSE) is a significant eruption of pure magic and solar plasma from the sun's corona during a silversun phase, when the sun experiences increased solar activity. Although it is known to be formed during explosive reconfigurations of the lower corona, no broadly accepted theory has been established explaining the exact mechanisms at work.

If a SSE reaches Sornieth it can cause fluctuations in the power of magic, geomagnetic and geomagical storms, aurorae, and potentially damage anything using magic or electricity. An extremely large SSE is responsible for the infusion of magic in Sornieth when a SSE hit the planet during its formation. As Sornieth was the only one directly in the SSE's path, it became the only planet in the system with magic.
The failing of the mega-reactor and resulting explosion that drew the Second Age to a close is also thought to be the result of another large SSE disrupting the magic being harnessed by the machine.

Properties

When the motion of the sun's interior contorts its own magnetic and magical fields they eventually explosively realign, driving vast amounts of energy into space from the corona. SSEs can be viewed through a solar telescope as enormous fans of silver gas swelling into space.
These large clouds of magic embedded in solar plasma expand as they travel through space, often reaching many millions of kilometres across and can travel between 10 km per second to more than 2000 km per second.
SSEs only occur during silversun phases during which time up to three SSEs a day may be produced. Silversun phases occur once every 11 years but the duration can vary from 9 to 14 years. Due to unknown phenomena during this period, solar activity such as solar flares, sunspots, and SSEs take on a silver hue no matter how they are imaged.

Impact on Sornieth

Only a very small amount of SSEs are directed at and reach Sornieth, however if they do they can have dramatic effects.
When the planet was still forming and before it had settled into a more solid shape it was hit by a large SSE. The pure magic contained in the plasma was injected deep into the core of the planet and fused with it. Consequently Sornieth suffered years upon years of explosive tumult and took much longer to form into a world, but eventually became the only planet in the system to have magic.

If a SSE collides with the planet's magnetic and magical fields today, it may generate geomagnetic and geomagical disturbances.
The wave of magical energy causes a geomagical storm that can temporarily increase the power of anything using magic, with extremely powerful SSEs potentially causing damage to magically-powered objects and users of magic if it overpowers them.
This is possibly what brought the Second Age to an end. It is suspected that a massive SSE, comparable to the one that struck while Sornieth was still forming, hit the planet and overcharged the mega-reactor to such a degree that it exploded causing a mass extinction. SSEs of this size are incredibly rare and powering down any objects before a large SSE hits and avoiding magic use during the event can provide protection from the worst effects. Starfall Isles are the most susceptible to the effects of geomagical storms.

The disruption to the magnetic field causes a similar geomagnetic storm which can cause damage to electrical systems from the currents the storm induces in them which may result in blackouts that may take days, months, or even years to repair. The Shifting Expanse is the worst hit by such an event. Although again there are precautions that can be taken to help prevent the worst case scenario, such as disconnecting equipment and temporary blackouts.

A much more harmless effect is aurorae; beautiful bands or curtains of colour filling the sky, caused by disturbances in the magnetosphere the SSE creates by enhancing the speed of the solar wind.

Future risk

The chance of Sornieth being hit by a SSE in the next decade that's large enough to cause a similar level of damage as the one which ended the Second Age has been calculated variously as being between 0.46% and 12%.
The Arcanist is always on watch for various space events including SSEs. Using his observations and other data, scientists can predict when a SSE will hit Sornieth and alert any appropriate groups allowing them to take precautions.