Astronomers discover a spectacular star stream stretching between galaxies

The black streak is the newly discovered Giant Coma Stream. This line is ten times as long as our Milky Way and is located about 300 million light years away between galaxies (the yellow spots). Credit: William Herschel Telescope/Román et al

Astronomers have made an exciting discovery: a massive stream of stars, stretching far beyond any single galaxy.

This discovery, published in the journal Astronomy & Astrophysics, is a first-of-its-kind find, marking the largest star stream ever observed.

The journey to this discovery began with a modest 70-centimeter telescope in California, operated by astronomer Michael Rich.

The initial observations were intriguing enough to prompt further investigation using the larger 4.2-meter William Herschel telescope in Spain.

After careful image processing, the astronomers uncovered a faint but vast stream of stars, more than 10 times the length of our Milky Way galaxy.

Floating amidst a cluster of galaxies, this stream, named the Giant Coma Stream, does not seem to belong to any single galaxy.

Javier Román, the lead researcher from the University of Groningen in the Netherlands and the University of La Laguna in Spain, explains that this discovery was somewhat accidental.

The team was initially studying star halos around large galaxies when they stumbled upon the Giant Coma Stream.

The existence of such a stream is quite remarkable. It’s a delicate structure located in a chaotic environment where galaxies are constantly moving, sometimes attracting and sometimes repelling each other.

Reynier Peletier, a co-author from the University of Groningen, notes that while computer simulations have predicted such massive streams, this is the first time one has been observed.

With this discovery, astronomers anticipate finding more giant star streams, especially with the help of future telescopes like the 39-meter ELT (Extremely Large Telescope) and the Euclid space telescope.

The team’s ambitions don’t stop at just finding new streams. They’re especially excited about studying the Giant Coma Stream in more detail.

By observing individual stars within this stream, they hope to gather more information about dark matter, a mysterious substance that makes up a significant part of the universe’s mass but remains invisible and undetectable by conventional means.

The Coma Cluster, where this stream was found, is a well-known cluster of thousands of galaxies located about 300 million light-years away in the constellation Coma Berenices. It was in this cluster that Swiss astronomer Fritz Zwicky, in 1933, first proposed the existence of dark matter.

He observed that the galaxies in the cluster moved too quickly to be held together only by the visible matter. This led to the hypothesis of dark matter, an unseen force holding these galaxies together.

The discovery of the Giant Coma Stream not only adds a new chapter to our understanding of the cosmos but also highlights the continual surprises and mysteries of our universe, waiting to be unraveled by the curious eyes of astronomers.

Source: KSR.