Hubble Space Telescope Takes Another Look at 'Weird' Galaxy That Seems to Lack Dark Matter - Gizmodo
In 2018, a team of astronomers reported that a galaxy appeared to have no dark matter, the invisible, mysterious stuff that is known only from its gravitational effects.
The team’s work was met with skepticism, but now, they’ve doubled-down on the hypothesis after additional observations of the galaxy using the Hubble Space Telescope.
Fewer stars would mean that less of DF2's gravity could be attributed to visible matter, and thus it must have more dark matter to hold the structure together.
“For almost every galaxy we look at, we say that we can’t see most of the mass because it’s dark matter,†van Dokkum said.The estimated distance of the galaxy was refined to about 22 megaparsecs, or 72 million light-years, making it even more distant than its previous estimated distance of 65 million light-years and defying the idea that its seeming lack of dark matter could be explained by a miscalculation of its distance.
More: Heated Debate Surrounds Galaxy Seeming to Lack Dark Matter.