The team of astronomers from the United States and Canada discovered the first super-diffuse galaxy called NGC 1052-DF2 (DF2 for short) with virtually no dark matter.
It is known that the DF2 galaxy is about the same size as our Milky Way galaxy, but only 1/200 stars. It is located in the constellation Cetus, about 65 million light-years away and a member of the galaxy group NGC 1052 . Now a similar galaxy has been discovered.
The newly discovered galaxy is called NGC 1052-DF4 (DF4 for short) , similar to DF2 in size, brightness, morphology, and has a similar distance of 65 million light years, without any matter inside. every night
Astronomers say, like DF2, DF4 belongs to a group of galaxies discovered recently known as ultra-diffuse galaxies (UDGs) .
They are as big as the Milky Way, but there are 100 to 1,000 times fewer stars, making them appear blurry so it is difficult to observe.
The discovery of these galaxies is difficult to explain in gravitation laws on a large scale, but is an important premise to support the hypothesis that dark matter exists.