General relativity predicts that when a large-enough rotating star collapses at the end of its life, it will collapse into a ring singularity, and this ring conserves angular momentum. When a typically-sized star (large enough to collapse into a black hole) rotating at a typical speed collapses into a ring singularity, how fast does the ring rotate (in terms of revolutions per second)? Also, what's the diameter of the ring? What would the rotational speed and diameter of the ring be for a humongous star, such as VY Canis Majoris? Also, in both cases: What would the dimensions and shape of the event horizon be?