Astronomers have recently found a new galaxy that does not have any dark matter. The new galaxy without dark matter is named NGC 1052-DF4. In March 2018, the researchers at Yale University had claimed about such a galaxy, which has no black matter. This claim had faced a lot of praise as well as criticism. This discovery was criticized because it totally contradicts the existing dark matter theory. However, recently, the discovery of the second galaxy has been confirmed. The team that discovered this was led by Pieter van Dokkum, Sol Goldman Family Professor of Astronomy. This discovery supports the old observations done in March 2018. However, the researchers also say that all the previously held assumptions need to be re-thought.
In this galaxy, dark matter is not found; however, most of the mass in the universe is due to dark matter. Our galaxies are made up of both- dark and normal matter. But, this discovery was somewhat a surprise to the researchers. The team is fascinated to see something like this for the first time. Shany Danieli, the researcher who first spotted this galaxy, said that no one knew about the existence of such galaxies. A discovery of any space objects, whether a star, a planet or a galaxy is the best thing for anyone studying astronomy.
For this discovery, the researchers observed the movements of ten-star clusters. This let them ascertain about the mass present in every galaxy. The galaxies contained the mass just as much as the stars would normally have. This led to a conclusion that only normal matter will be present in the galaxy. Dokkum also said that with this discovery, it is sure that there could be many more such galaxies in the universe. Until now, there was an understanding of galaxies that they cannot exist without dark matter. But, current discoveries will encourage the researchers to rethink and know more. The older galaxy DF2 and the current one DF4 are called ultra-diffuse galaxies. They are almost of similar size as Milky Way is, but has lesser stars comparatively.