The debates in astronomy are fascinating; These are usually exciting and often do not tell us that we understand very little. The Galaxy Dragonfly 2 (DF2) could be a perfect example. After it was discovered, it was announced that it could be a galaxy without dark matter. Exciting and wonderful! Since then more galaxies have been discovered and follow-up observations have revealed a different group that DF2 and others were much closer than the original measurements. Based on this, they suggested that it meant they weren’t as big as they used to be and so they didn’t actually lack darkness.
But now another turning point has happened. The original team again observed DF2 and proved that it was not the distance it was originally estimated. It’s further away from us! (Row of dramatic music) The new observations were made thanks to the deep interest of the Hubble Space Telescope. New discoveries have been published in the Astrophysical Journal Letter and the distance to DF2 is now estimated at 72 million light-years. The team estimates that in this galaxy it should be 1/400th of the dark matter.
Senior author Professor Pieter van Dokkum, from Yale University, said in a statement, “We came out in 2018 with an organ with our initial Hubble observations of this galaxy.” “I think it was okay for people to question it because it’s such an unusual result. It would be nice if there was a general explanation like a wrong distance. But I think it’s more fun and more interesting if it’s a very strange galaxy.” The old red giant saw the stars and gained new distance. All of these objects have reached the same peak peak brightness in their evolution, which researchers can use to estimate their distances. These are a kind of illuminated milestones.
“Studying bright red giants is a well-established distance indicator for nearby galaxies,” explained lead author Jelly Shen, a graduate researcher at Yale University. Matter remains a conjectural substance. It was theoretical to explain the strange rotation of the galaxy, but its true nature has not yet been determined, even after various experiments. For this reason, some have suggested that there is no such thing as dark matter but that we must rewrite the laws of physics. Instead the existence of DF2 and similar galaxies gives a clear indication that dark matter is a substance.
