Pieter van Dokkum

A runaway supermassive black hole leaves a superheated gas tail visible from Earth. The James Webb Space Telescope clocked its escape velocity at 954 km/s, revealing that such giants can be flung from their galaxies.

Three dwarf galaxies in the constellation Cetus lack dark matter. Velocity measurements in DF9 showed: stars crawl like pedestrians, instead of racing as usual. This pace indicates mass from visible stars only. Likely, all three arose when a galaxy collision filtered gas from dark matter, like a kit