Judging by the information astrophysicists have, any galaxy should contain a significant amount of dark matter, the mysterious form of matter that’s responsible for some of the stars’ movements within galaxies. But as it always happens in astronomy, the Universe is right there laughing in the scientists’ face and ready to prove them wrong.
NASA speaks about the case of a peculiar galaxy that lacks the predicted amount of dark matter – a massive portion of it, defying the usual models. The galaxy in question is NGC 1052-DF2, or simply DF2, as the scientists call it. The galaxy was found using the good old Hubble Space Telescope that’s operated by NASA and the European Space Agency.
The galaxy was discovered in 2018, and now, a team of scientists having Pieter van Dokkum as the leader, who is a scientist from Yale University in New Haven, Connecticut, are bolstering their initial study by taking another look at the galaxy using the Hubble telescope.
Dokkum declared while cited on NASA’s website:
We went out on a limb with our initial Hubble observations of this galaxy in 2018,
I think people were right to question it because it’s such an unusual result. It would be nice if there were a simple explanation, like a wrong distance. But I think it’s more fun and more interesting if it actually is a weird galaxy.
Therefore, trying to understand exactly the cause of the missing dark matter from the DF2 galaxy is a major challenge. According to Zili Shen from Yale University, the new Hubble observations are confirming that DF2 is farther from Earth than the previous estimations were claiming, and it’s also more distant. The new observations reveal that DF2 is 72 million light-years compared to only 42 million light-years, as reported by other teams. This places the DF2 galaxy farther than the original Hubble estimation.