Seyllin is a solar system in the Essence region of the Gallente Federation. The system is home to nine planets, most of them unremarkable, except for Seyllin I, which was heavily damaged in a stellar disaster that occurred March 10th, YC111.
Seyllin was originally known as TLXX-01, an unexplored system on the fringes of Federation space. In YC 51, Braggs Seyllin, a former executive at Material Acquisition, first explored the system in an effort to make a fortune. In TLXX-01, Seyllin struck gold, literally, when he surveyed the first planet in the system and discovered rich deposits of valuable heavy metals.
Seyllin acquired enough venture capital through investments to establish mining colonies on the planet. Within a few years, the investments had paid off tens of times over. The value of the single planet eventually brought other colonists and interests to the system, which was eventually renamed after Seyllin a decade after his death in YC91. By YC111, the planet accounted for a quarter of all raw ore production in the Thoulde constellation and a significant fraction of the Federation's supply of heavy metals and was home to a half billion people.
The system remained an important and vital part of the Federation's economy until March 10th, YC111. The first indication of what was to come was the sudden disruption of electronics at "Cassandra", a solar monitoring station in the system. Shortly after, electronics on Seyllin I were disrupted and all communication with the system was cut off. This was the result of a massive burst of radiation from the sun.
Roughly 10 minutes later, communications were reestablished with the system, flooding emergency channels with distress calls. The initial messages received were confused and jumbled, mainly being pleas for assistance, drawing fears of a nuclear assault on the planet.
This initial radiation burst killed millions on the planet, wiping out the majority of the sun-side population and bathing the entire population in varying amounts of deadly radiation. Scientists initially described the disaster as a "post-main sequence event" and were unable to rule out the possibility the sun had gone supernova. CONCORD and the Federation Navy scrambled warships to provide protection and humanitarian aid to the survivors. Shortly after, President Souro Foiritan and CONCORD Chief of Staff Kivas Odaka released a joint statement about the incident, announcing a plan to evacuate the planet.
Orbital triage centers were established soon after, while ORE and traditional Federation antagonists Serpentis sent relief ships to assist. However, rescue attempts were chaotic, with two drop ships colliding, while panicked survivors transmitted distress calls to civilian ships. Those attempting to use the planet's magrail were trapped as the system failed.
Relief workers expressed horror and dismay over the events. One rescue team member described the conditions as "hell", while another gave those survivors beneath the planet's sun side little chance of survival.
After several hours of evacuation attempts, CONCORD probes investigating the sun suddenly vanished. Soon after, CONCORD reported a large mass of plasma accelerating toward the planet, apparently ejected from the sun. Rescue operations were disrupted by panicked citizens, forcing marines to open fire on the population. As a "zero-hour" approached, all relief ships pulled out of the system and a blockade was established, preventing further ships from entering the system. Shortly after, communications from the system were once again disrupted.
Several minutes later, the first contact from the system came from a Serpentis freighter that had been trapped in the system. The freighter reported that the first planet had been obliterated. Shortly after, CONCORD dropped its blockade with President Foiritan releasing a statement confirming the planet's destruction shortly after. The Scope released images shortly after, showing the remains of the planet collapsing back under gravity, producing an image compared to the late stages of planetary formation.
Of the half-billion residents of the planet, only a million had been successfully evacuated. In the following months, the planet continued its slow coalescing and reformation, as travel through the system returned to normal levels. The destruction of Seyllin I was a major blow to the Federation economy. The stellar ejection event led to a change in the star's stellar classification, from Type-O to Type-A.
Seyllin is a blue main sequence A-class star. Prior to March 10, YC111, it was a blue-white O-class main sequence star, but the stellar ejection event reduced its mass significantly, causing it to drop in size and luminosity. The star has not yet stabilized from the ejection, with massive gravitational and electromagnetic fluctuations. It is prone to solar flares and sudden shifts in brightness and energy output.
The star is just over 2 billion years old. As an O-class star, it was nearing the end of its main sequence life and was expected to go supernova in roughly a million years. Because of the unprecedented nature of the disaster, scientists are unsure of the star's final fate. Additionally, the change in mass has destabilized the orbits of its planets. The changes will be minor for the near future, but on the order of tens of thousands of years, some planets may be ejected from the system or move closer or further from the star.
Seyllin I was the primarily inhabited planet in the system. Originally a barren planet, it was host to numerous rich deposits of valuable heavy metals such as gold, iron, vanadium, and tungsten. The planet was colonized following its discovery by Braggs Seyllin and quickly became a vital part of the Federation's economy and heavy metal production.
As large tunnels were carved out underground and left empty, subterranean terraforming attempts were made. These attempts were successful in introducing fresh water, vegetation, artificial sunlight, and breathable atmospheres. At its peak, four cities had been established on the planet: Loadcore, Metal City, Southern Cross, and Valimor. The cities were home to a half-billion people.
On March 10, YC111, the planet was struck by two consecutive disasters originating from its sun. The first, which struck at around 8:49 EVE Standard Time, was a pulse of radiation that killed thousands on the planet's sun-side surface and caused acute radiation poisoning in those beneath the sun-side surface. The second occurred several hours later, when a large mass of plasma ejected from the star struck the planet. The collision destroyed the planet, killing the population that had not been evacuated.
Following the planet's destruction, its remnants remained gravitationally bound and slowly began to collapse back into a planet. Once this process is complete, the planet's structure could be drastically changed, but should still contain the majority of its metal deposits. However, this process is expected to take thousands of years.
Seyllin II is an unremarkable barren planet. Because of its closeness to the Seyllin sun, it is a hot, blasted world. Prior to the stellar ejection, surface temperatures were nearly as hot as on Seyllin I. They have dropped since the change in the star's luminosity, but still make the surface inhospitable. Unlike Seyllin I, the planet does not possess rich deposits, and has not been exploited in any major sense.
Despite being a temperate world, Seyllin III is not home to any life. Because it was bombarded by heavy amounts of solar radiation for nearly a billion years, life was never able to form on its surface. Thus it does not have a breathable atmosphere, though it does have large surface oceans. Under natural conditions, the planet would have been destroyed by the star's supernova or, barring that, eventually lost the majority of its atmosphere and surface water and become a barren planet.
With the change in luminosity of the star, it is uncertain what will happen with the planet. There is the possibility of life eventually forming on the planet, but no one is sure if the star will stabilize or become less luminous or even expand into a red giant and devour the planet.
A gravitational magmatic, Seyllin IV is constantly subject to intense turmoil that keeps it heated and hot. Combined with its closeness to a former Type-O star, the planet was never able to cool sufficiently to form a surface crust. Geologists suspect that thanks to the drop in the star's luminosity, Seyllin IV will finally be able to cool sufficiently so its gravitational energy will not be enough to keep it superheated. This process will take millions of years, however, as the planet maintains a large amount of stored internal heat.
Another blasted, barren rock, Seyllin V has very little of interest. When the local star was a Type-O, it was subject to intense radiation and heat. Following the stellar ejection, the planet receives a much lesser bombardment and has cooled significantly. Because it maintains no atmosphere to trap heat, the planet is now much cooler, which has caused large cracks to form over the planet as its surface has contracted.
The thick atmosphere of Seyllin VI's trapped the heat of the O-type star, turning it into a roiling mass of superheated gas. Intense plasma storms rage over the planet's surface, leaving it a lump of semi-molten rock. The storms disrupt electronics, even those that are heavily shielded, making exploration and exploitation of the planet difficult.
With the drop in luminosity of the local star, it is expected that Seyllin VI will slowly cool. However, because its thick atmosphere creates an intense greenhouse, this process is likely to take thousands of years to complete.
Much like its terrestrial twin of Seyllin III, Seyllin VII has surface water and a significant atmosphere, but because of solar radiation, life never had the chance to form. The atmosphere is composed mostly of nitrogen and carbon dioxide as a result. Had nature been allowed to take its course, it would have been destroyed in the sun's supernova before any biological processes could have begun.
The drop in the star's luminosity has changed its fate entirely, though life still seems unlikely. Instead, the planet is far outside the sun's new habitability zone. As the planet's atmosphere slowly loses heat, it is expected that the planet will cool and eventually become covered in glaciers. This process is expected to take several decades to complete.
Even when its star was Type-O, Seyllin VIII was a fairly standard gas giant. It received a good deal of heat, but was far enough to not become a pegasean planet. With the drop in its stars luminosity, it has cooled further. It is currently harvested for helium and hydrogen.
A distantly orbiting gas giant, Seyllin IX was the planet least directly affected by the stellar ejection of its star. However, it may be the planet most impacted long term, as astrophysicists believe that within ten thousand years, the planet will be ejected from the system due to the star's drop in mass.