The Yggdrasil Nebula is a very large emission nebula within the Via Sagittaria Galaxy. The nebula contains many massive star-clusters as well as several Wolf-Rayet stars. The nebula is one of the largest nebulae in Via Sagittaria.
The Yggdrasil Nebula is the center of Vanaheimr, a nation founded by a human minority group in 21,387 CE. Vanaheimr quickly came to control the majority of the Nebula by 21,591 CEand very shortly after expanded to the regions surrounding it. The treaty creating the Confederacy of Borealis was first drafted in the nebula before negotiations were moved to another location. Other major events include the creation of the Confederacy's Congress, what became the governing body over the Confederacy, as well as the restoration of democracy in the Via Sagittaria after the Split of the Yohjan Confederacy.
The nebula is home to one of the most luminous stars in the Via Sagittaria, Sygin, a binary between a luminous blue variable and an evolved O type star. This star is currently used as a source for a large amount of the energy used in the Nebula at over 50% of it's energy. The star shines with 5 million solar luminosities, and it is also extremely bright visually with an absolute magnitude of ~-10. A civilization using all of this energy would be a kardashev 2.7 civilization by itself. Vanaheimr is currently in the process of tapping into the entirety of this energy, but it progress has been slow.
The nebula also has a few smaller nebulae within itself such as the Homunculus Nebula, Keybole Nebula and the Mystic Mountain.
The Yggdrasil Nebula has been speculated to be where the home world of the First Civilization was located due to their artifacts being more numerous in the nebula than elsewhere. The exact location is unknown, but was most likely the planet Frigg-AHG, a planet that does not have a name besides it's designation. Frigg-AHG is located forty light-years from Jörmungandr, the capital of Vanaheimr.
The Yggdrasil Nebula was first visited by humans in about 12,500 BCE. The mission was likely one to secure the rare resource called Eitr only found within the galaxy. While few colonists entered the galaxy before the common era, large numbers of refugees flooded into the region in response to the War of the Final Transition and, later, the Great Empyreal Crusade.
The Nebula would later become the center of democracy in the Via Sagittaria. The Split of the Yohjan Confederacy left the galaxy in an authoritarian state. With true democracy as a rare sight. Vanaheimr began spreading its system to elsewhere in the galaxy. They began, often aggressively, pushing for democracy in neighboring nations, inspiring worker revolutions wherever they went. Leading this movement was Frejya Zhang whose ambition and knack for diplomacy allowed for many worlds to come under the umbrella of the democracy. Vanaheimr would go on to be the first signer of the treaty which established the Confederacy of Borealis, a largely democratic institution.
In more recent times, the nebula has remained as the center of democracy in the Confederacy. It acts as the electoral capital of the Confederacy of Borealis. The difficultly in coordinating elections on a galactic scale requires so much planning that an entire planet was set aside for just that. The Yggdrasil Nebula was the natural choice for the electoral capital being the cradle of modern democracy as it was.