https://www.sciencealert.com/galaxy-ncg1052-df2-no-dark-matter-ultra-diffuse-dragonfly-array
"Finding a galaxy without dark matter is unexpected because this invisible, mysterious substance is the most dominant aspect of any galaxy," said lead author Pieter van Dokkum of Yale University.
"For decades, we thought that galaxies start their lives as blobs of dark matter. After that everything else happens: gas falls into the dark matter halos, the gas turns into stars, they slowly build up, then you end up with galaxies like the Milky Way. NGC1052-DF2 challenges the standard ideas of how we think galaxies form."
In addition, the galaxy has huge implications in the study of dark matter. Because - simply by having none, but having stars - NCG1052-DF2 helps to prove that dark matter really exists in other galaxies and is separate from baryonic matter.