An international research team has discovered a stream of giant and extremely faint stars between galaxies. Although streams are already known in our galaxy and neighboring galaxies, this is the first time a stream flowing between galaxies has been observed. This is the largest flow discovered to date. The astronomers published their findings in the journal Astronomy & Astrophysicals.

The first observations were made by the relatively small 70-centimeter telescope of astronomer Michael Rich in California (United States). The researchers then focused the 4.2-meter William Herschel Telescope (La Palma, Spain) on the area. After processing the image, they saw an extremely weak stream whose length was more than ten times the length of the Milky Way. The stream appears to flow in the cluster environment and is not associated with any particular galaxy. Researchers call this the Giant Coma Flow.

“This huge stream happened to come our way,” explains lead researcher Javier Roman. It is a branch of the University of Groningen (Netherlands) and the University of La Laguna in Tenerife (Spain). “We studied stellar halos around large galaxies.”

The discovery of the Giant Comet Stream is remarkable because it is a very fragile structure in a hostile environment created by the attraction and repulsion of galaxies against each other. Co-author Rainier Pelletier (University of Groningen, Netherlands) explains: “By the way, we were able to simulate such large flows on the computer. So we hope to find more. For example, if we look at the 39-meter ELT in the future and when Euclid starts generating data.” “

With the help of future large telescopes, researchers hope to discover new giant streams. They also want to expand the Giant Coma Current. “We want to observe individual stars in and around the stream and learn more about dark matter,” says Pelletier.

The Coma Cluster is one of the most studied galaxy clusters. It contains thousands of galaxies in the northern constellation Veronica, about 300 million light-years from Earth. In 1933, Swiss astronomer Fritz Zwicky showed that the galaxies in the cluster were moving very fast, considering only the amount of visible matter. He realized that there must be dark matter holding everything together. The exact nature of dark matter is still unknown.