Astronomers have discovered for the first time the existence of huge streams of stars between galaxies. The black stripes from left to right in the picture are the newly discovered Giant Coma Stream, and the yellow spots are different galaxies. (William Herschel Telescope/Román et al.)
[The Epoch Times, December 07, 2023](Epoch Times reporter Chen Juncun reported) An international research team discovered a huge and extremely weak star stream between galaxies, which is more than 10 times as long as the Milky Way. This is the first time astronomers have discovered a star stream between galaxies, and it is also the largest star stream ever observed. The discovery took them by surprise.
According to the Live Science website, stellar streams are long structures formed by stars entangled by gravity. These stars may have been pulled by the gravity of other nearby galaxies and left their original galaxies or nebulae.
Astronomers have previously discovered dozens of such star streams in many galaxies, including the Milky Way, but this is the first time researchers have observed star streams between galaxies.
The Netherlands Research School for Astronomy pointed out in a press release that American astronomer Michael Rich was the first to observe a star stream between galaxies using a relatively small 70-centimetre telescope in California.
Then, members of the research team observed the area with the 4.2-meter William Herschel Telescope in Spain.
After processing the images, the researchers saw an extremely faint star stream that was more than 10 times the length of our Milky Way. The stream appears to be floating in a galaxy cluster environment and is not associated with any particular galaxy. Researchers named this stream the Giant Coma Stream.
The Coma Cluster is one of the most studied galaxy clusters by scientists. The cluster contains thousands of galaxies. It is located in the direction of Coma Berenices, about 300 million light-years away from Earth.
Javier Román, a researcher at the University of Groningen in the Netherlands and the University of La Laguna in Spain, who led the study, explained: “This huge star stream happened to pass through our Observation path. We are studying star halos around large galaxies.”
Researchers say the discovery of the giant Coma stream is remarkable because it is a rather fragile structure in a harsh environment where galaxies attract and repel each other.
Reynier Peletier, a researcher at the University of Groningen and one of the authors of this study, said that they have simulated such a huge star stream on a computer and expect to find more.
Pelletier also said that with the help of future large telescopes, researchers hope to discover new giant star streams and also focus on the giant coma star stream.
“We want to observe individual stars in and near this stream to learn more about dark matter,” he said.
The above research results were published in the journal Astronomy and Astrophysics on November 30.
Editor in charge: Ye Ziwei#
