From, https://www.syfy.com/syfywire/wham-...eates-a-ring-of-black-holes-and-neutron-stars ..."“So you have a nice, normal spiral galaxy, right, just out there doing its thing, when BAM! A smaller galaxy careens right through the middle of it like a bullet! Chaos, fireworks, explosions everywhere! And then, after the second galaxy leaves, the first one starts changing shape, transforming, into a big ring, and then stars start dying, and now there’s this huge ring a gazillion miles across that’s just littered with black holes and other weird objects sucking down matter and spewing out death rays!”" ... ..."That’s why AM 0644 looks blue! When clouds form stars, many of them are massive and hot, so they shine blue. Also, they don’t live long; these massive stars go through their fuel in a million or tens of millions of years. When that happens they explode, leaving behind either an extremely dense ball called a neutron star or a black hole."