Okay, so after redoing the calculations, the Schwarzschild Radius for a sphere of pure water of diameter 55000 light years is 1.14^10^38 metres. The radius of such a sphere in metres would be 5.203 * 10^20 metres, which actually is less than the Schwarzschild radius.
However, we can switch this out for earth, which has a solid density of 5515 kg/m^3.
The mass of this planet would be 4.06823×10^65 kg.
The Schwarzschild Radius for this planet would be 6.041×10^38 meters...? Which is apparently more than the Radius for water even though Earth is far more dense... So never mind about the planet collapsing in on itself and becoming a black hole.
However, we can switch this out for earth, which has a solid density of 5515 kg/m^3.
The mass of this planet would be 4.06823×10^65 kg.
The Schwarzschild Radius for this planet would be 6.041×10^38 meters...? Which is apparently more than the Radius for water even though Earth is far more dense... So never mind about the planet collapsing in on itself and becoming a black hole.