MSG 519 is one of the strangest objects found in the vicinity of Via Sagittaria, and the only example of what is known as a Boson Star within 1 million light years of the galaxy. This little ball of gas and bosons is located in the Vent-Our Stream - a giant 'ribbon' of gas connecting the Ouranir Galaxy and Ventemir Galaxy. Although it is located there, it did not form there. 519 is in fact incredibly old - 13.71 billion old. It formed only 90 million years after the big bang.
MSG 519 was discovered during the Vent-Our Stream Survey, that lasted around 40 years, from 18286 to 18326 CE. It catalogued around 35 million objects, not including planets. Those were found as well, orbiting their parent stars.
Around 700 of these objects were not visible to the main cameras of the telescopes conducting this survey, and among them is MSG 519. MSG 519 was the 519th one to be discovered of these. It was also the 16th brightest of the MSG objects. Then, it would sadly fall to the wayside of things, until 22636 CE, when an independent Aeros-based astronomer whose name is not known, came up with an idea - launch probes towards the MSG objects. His idea slowly gained traction over the years, and in 22641 CE, it was officially commissioned to the Confederacy of Borealis, and the probes were constructed in no time, using the finest technology available at the time.
On 15th September 22641 CE, the probes were shot towards their 721 targets, and using wormholes, they cut their treacherous journey and arrived to their destinations at around February 22642 CE. Now, nearly all of these were just black holes or clumps of dark matter, but MSG 519 was different. Data gathered at around 22644 CE showed it to have a surface, albeit a small one, and extremely cool.
MSG 519 was also extremely light - its mass was only half the mass of a typical brown dwarf, but it was also very dense, with a radius of only around 200 km. No similar object had ever been discovered. It was one of a kind for a very long time (until around 36000 CE), and many people studying it had no clue of what it might have been. One individual, whose name we do not know of currently, decided to run computer simulations of different objects to see which one could produce an object similar to this one. The only result, as astounding as it was, was a boson star. In 25301 CE, they published a science paper on their finds, which immediately received galaxy wide attention. This was very important and a momentous find, as MSG 519 was the first boson star ever discovered. Immediately, many probed missions were suggested and sent towards MSG 519, directed by many competitive groups of able astronomers. In a few years practically the entire history of the star was discovered by different astronomers.